fix: improvedr pair status sharing.

- pair_devices.html template for device pairing interface
- SLMM device control lock prevents flooding nl43.
Fix:
- Polling intervals for SLMM.
- modem view now list
- device pairing much improved.
- various other tweaks through out UI.
- SLMM Scheduled downloads fixed.

backend/main.py

@@ -21,6 +21,7 @@ from backend.database import engine, Base, get_db
 from backend.routers import roster, units, photos, roster_edit, roster_rename, dashboard, dashboard_tabs, activity, slmm, slm_ui, slm_dashboard, seismo_dashboard, projects, project_locations, scheduler, modem_dashboard
 from backend.services.snapshot import emit_status_snapshot
 from backend.models import IgnoredUnit
+from backend.utils.timezone import get_user_timezone
 
 # Create database tables
 Base.metadata.create_all(bind=engine)
@@ -223,6 +224,67 @@ async def modems_page(request: Request):
     return templates.TemplateResponse("modems.html", {"request": request})
 
 
+@app.get("/pair-devices", response_class=HTMLResponse)
+async def pair_devices_page(request: Request, db: Session = Depends(get_db)):
+    """
+    Device pairing page - two-column layout for pairing recorders with modems.
+    """
+    from backend.models import RosterUnit
+
+    # Get all non-retired recorders (seismographs and SLMs)
+    recorders = db.query(RosterUnit).filter(
+        RosterUnit.retired == False,
+        RosterUnit.device_type.in_(["seismograph", "slm", None])  # None defaults to seismograph
+    ).order_by(RosterUnit.id).all()
+
+    # Get all non-retired modems
+    modems = db.query(RosterUnit).filter(
+        RosterUnit.retired == False,
+        RosterUnit.device_type == "modem"
+    ).order_by(RosterUnit.id).all()
+
+    # Build existing pairings list
+    pairings = []
+    for recorder in recorders:
+        if recorder.deployed_with_modem_id:
+            modem = next((m for m in modems if m.id == recorder.deployed_with_modem_id), None)
+            pairings.append({
+                "recorder_id": recorder.id,
+                "recorder_type": (recorder.device_type or "seismograph").upper(),
+                "modem_id": recorder.deployed_with_modem_id,
+                "modem_ip": modem.ip_address if modem else None
+            })
+
+    # Convert to dicts for template
+    recorders_data = [
+        {
+            "id": r.id,
+            "device_type": r.device_type or "seismograph",
+            "deployed": r.deployed,
+            "deployed_with_modem_id": r.deployed_with_modem_id
+        }
+        for r in recorders
+    ]
+
+    modems_data = [
+        {
+            "id": m.id,
+            "deployed": m.deployed,
+            "deployed_with_unit_id": m.deployed_with_unit_id,
+            "ip_address": m.ip_address,
+            "phone_number": m.phone_number
+        }
+        for m in modems
+    ]
+
+    return templates.TemplateResponse("pair_devices.html", {
+        "request": request,
+        "recorders": recorders_data,
+        "modems": modems_data,
+        "pairings": pairings
+    })
+
+
 @app.get("/projects", response_class=HTMLResponse)
 async def projects_page(request: Request):
     """Projects management and overview"""
@@ -587,6 +649,7 @@ async def devices_all_partial(request: Request):
             "last_calibrated": unit_data.get("last_calibrated"),
             "next_calibration_due": unit_data.get("next_calibration_due"),
             "deployed_with_modem_id": unit_data.get("deployed_with_modem_id"),
+            "deployed_with_unit_id": unit_data.get("deployed_with_unit_id"),
             "ip_address": unit_data.get("ip_address"),
             "phone_number": unit_data.get("phone_number"),
             "hardware_model": unit_data.get("hardware_model"),
@@ -610,6 +673,7 @@ async def devices_all_partial(request: Request):
             "last_calibrated": unit_data.get("last_calibrated"),
             "next_calibration_due": unit_data.get("next_calibration_due"),
             "deployed_with_modem_id": unit_data.get("deployed_with_modem_id"),
+            "deployed_with_unit_id": unit_data.get("deployed_with_unit_id"),
             "ip_address": unit_data.get("ip_address"),
             "phone_number": unit_data.get("phone_number"),
             "hardware_model": unit_data.get("hardware_model"),
@@ -633,6 +697,7 @@ async def devices_all_partial(request: Request):
             "last_calibrated": unit_data.get("last_calibrated"),
             "next_calibration_due": unit_data.get("next_calibration_due"),
             "deployed_with_modem_id": unit_data.get("deployed_with_modem_id"),
+            "deployed_with_unit_id": unit_data.get("deployed_with_unit_id"),
             "ip_address": unit_data.get("ip_address"),
             "phone_number": unit_data.get("phone_number"),
             "hardware_model": unit_data.get("hardware_model"),
@@ -656,6 +721,7 @@ async def devices_all_partial(request: Request):
             "last_calibrated": None,
             "next_calibration_due": None,
             "deployed_with_modem_id": None,
+            "deployed_with_unit_id": None,
             "ip_address": None,
             "phone_number": None,
             "hardware_model": None,
@@ -678,7 +744,8 @@ async def devices_all_partial(request: Request):
     return templates.TemplateResponse("partials/devices_table.html", {
         "request": request,
         "units": units_list,
-        "timestamp": datetime.now().strftime("%H:%M:%S")
+        "timestamp": datetime.now().strftime("%H:%M:%S"),
+        "user_timezone": get_user_timezone()
     })
 
 

backend/routers/roster.py

@@ -2,20 +2,32 @@ from fastapi import APIRouter, Depends
 from sqlalchemy.orm import Session
 from datetime import datetime, timedelta
 from typing import Dict, Any
+import asyncio
+import logging
 import random
 
 from backend.database import get_db
 from backend.services.snapshot import emit_status_snapshot
+from backend.services.slm_status_sync import sync_slm_status_to_emitters
 
 router = APIRouter(prefix="/api", tags=["roster"])
+logger = logging.getLogger(__name__)
 
 
 @router.get("/status-snapshot")
-def get_status_snapshot(db: Session = Depends(get_db)):
+async def get_status_snapshot(db: Session = Depends(get_db)):
     """
     Calls emit_status_snapshot() to get current fleet status.
-    This will be replaced with real Series3 emitter logic later.
+    Syncs SLM status from SLMM before generating snapshot.
     """
+    # Sync SLM status from SLMM (with timeout to prevent blocking)
+    try:
+        await asyncio.wait_for(sync_slm_status_to_emitters(), timeout=2.0)
+    except asyncio.TimeoutError:
+        logger.warning("SLM status sync timed out, using cached data")
+    except Exception as e:
+        logger.warning(f"SLM status sync failed: {e}")
+
     return emit_status_snapshot()
 
 

backend/routers/roster_edit.py

@@ -10,6 +10,7 @@ import os
 
 from backend.database import get_db
 from backend.models import RosterUnit, IgnoredUnit, Emitter, UnitHistory
+from backend.services.slmm_sync import sync_slm_to_slmm
 
 router = APIRouter(prefix="/api/roster", tags=["roster-edit"])
 logger = logging.getLogger(__name__)
@@ -456,7 +457,7 @@ def get_roster_unit(unit_id: str, db: Session = Depends(get_db)):
 
 
 @router.post("/edit/{unit_id}")
-def edit_roster_unit(
+async def edit_roster_unit(
     unit_id: str,
     device_type: str = Form("seismograph"),
     unit_type: str = Form("series3"),
@@ -662,6 +663,16 @@ def edit_roster_unit(
 
     db.commit()
 
+    # Sync SLM polling config to SLMM when deployed/retired status changes
+    # This ensures benched units stop being polled
+    if device_type == "slm" and (old_deployed != deployed_bool or old_retired != retired_bool):
+        db.refresh(unit)  # Refresh to get committed values
+        try:
+            await sync_slm_to_slmm(unit)
+            logger.info(f"Synced SLM {unit_id} polling config to SLMM (deployed={deployed_bool}, retired={retired_bool})")
+        except Exception as e:
+            logger.warning(f"Failed to sync SLM {unit_id} polling config to SLMM: {e}")
+
     response = {"message": "Unit updated", "id": unit_id, "device_type": device_type}
     if cascaded_unit_id:
         response["cascaded_to"] = cascaded_unit_id
@@ -669,7 +680,7 @@ def edit_roster_unit(
 
 
 @router.post("/set-deployed/{unit_id}")
-def set_deployed(unit_id: str, deployed: bool = Form(...), db: Session = Depends(get_db)):
+async def set_deployed(unit_id: str, deployed: bool = Form(...), db: Session = Depends(get_db)):
     unit = get_or_create_roster_unit(db, unit_id)
     old_deployed = unit.deployed
     unit.deployed = deployed
@@ -690,11 +701,21 @@ def set_deployed(unit_id: str, deployed: bool = Form(...), db: Session = Depends
         )
 
     db.commit()
+
+    # Sync SLM polling config to SLMM when deployed status changes
+    if unit.device_type == "slm" and old_deployed != deployed:
+        db.refresh(unit)
+        try:
+            await sync_slm_to_slmm(unit)
+            logger.info(f"Synced SLM {unit_id} polling config to SLMM (deployed={deployed})")
+        except Exception as e:
+            logger.warning(f"Failed to sync SLM {unit_id} polling config to SLMM: {e}")
+
     return {"message": "Updated", "id": unit_id, "deployed": deployed}
 
 
 @router.post("/set-retired/{unit_id}")
-def set_retired(unit_id: str, retired: bool = Form(...), db: Session = Depends(get_db)):
+async def set_retired(unit_id: str, retired: bool = Form(...), db: Session = Depends(get_db)):
     unit = get_or_create_roster_unit(db, unit_id)
     old_retired = unit.retired
     unit.retired = retired
@@ -715,6 +736,16 @@ def set_retired(unit_id: str, retired: bool = Form(...), db: Session = Depends(g
         )
 
     db.commit()
+
+    # Sync SLM polling config to SLMM when retired status changes
+    if unit.device_type == "slm" and old_retired != retired:
+        db.refresh(unit)
+        try:
+            await sync_slm_to_slmm(unit)
+            logger.info(f"Synced SLM {unit_id} polling config to SLMM (retired={retired})")
+        except Exception as e:
+            logger.warning(f"Failed to sync SLM {unit_id} polling config to SLMM: {e}")
+
     return {"message": "Updated", "id": unit_id, "retired": retired}
 
 
@@ -1156,3 +1187,145 @@ def delete_history_entry(history_id: int, db: Session = Depends(get_db)):
     db.delete(history_entry)
     db.commit()
     return {"message": "History entry deleted", "id": history_id}
+
+
+@router.post("/pair-devices")
+async def pair_devices(
+    request: Request,
+    db: Session = Depends(get_db)
+):
+    """
+    Create a bidirectional pairing between a recorder (seismograph/SLM) and a modem.
+
+    Sets:
+    - recorder.deployed_with_modem_id = modem_id
+    - modem.deployed_with_unit_id = recorder_id
+
+    Also clears any previous pairings for both devices.
+    """
+    data = await request.json()
+    recorder_id = data.get("recorder_id")
+    modem_id = data.get("modem_id")
+
+    if not recorder_id or not modem_id:
+        raise HTTPException(status_code=400, detail="Both recorder_id and modem_id are required")
+
+    # Get or create the units
+    recorder = db.query(RosterUnit).filter(RosterUnit.id == recorder_id).first()
+    modem = db.query(RosterUnit).filter(RosterUnit.id == modem_id).first()
+
+    if not recorder:
+        raise HTTPException(status_code=404, detail=f"Recorder {recorder_id} not found in roster")
+    if not modem:
+        raise HTTPException(status_code=404, detail=f"Modem {modem_id} not found in roster")
+
+    # Validate device types
+    if recorder.device_type == "modem":
+        raise HTTPException(status_code=400, detail=f"{recorder_id} is a modem, not a recorder")
+    if modem.device_type != "modem":
+        raise HTTPException(status_code=400, detail=f"{modem_id} is not a modem (type: {modem.device_type})")
+
+    # Clear any previous pairings
+    # If recorder was paired with a different modem, clear that modem's link
+    if recorder.deployed_with_modem_id and recorder.deployed_with_modem_id != modem_id:
+        old_modem = db.query(RosterUnit).filter(RosterUnit.id == recorder.deployed_with_modem_id).first()
+        if old_modem and old_modem.deployed_with_unit_id == recorder_id:
+            record_history(db, old_modem.id, "update", "deployed_with_unit_id",
+                          old_modem.deployed_with_unit_id, None, "pair_devices", f"Cleared by new pairing")
+            old_modem.deployed_with_unit_id = None
+
+    # If modem was paired with a different recorder, clear that recorder's link
+    if modem.deployed_with_unit_id and modem.deployed_with_unit_id != recorder_id:
+        old_recorder = db.query(RosterUnit).filter(RosterUnit.id == modem.deployed_with_unit_id).first()
+        if old_recorder and old_recorder.deployed_with_modem_id == modem_id:
+            record_history(db, old_recorder.id, "update", "deployed_with_modem_id",
+                          old_recorder.deployed_with_modem_id, None, "pair_devices", f"Cleared by new pairing")
+            old_recorder.deployed_with_modem_id = None
+
+    # Record history for the pairing
+    old_recorder_modem = recorder.deployed_with_modem_id
+    old_modem_unit = modem.deployed_with_unit_id
+
+    # Set the new pairing
+    recorder.deployed_with_modem_id = modem_id
+    modem.deployed_with_unit_id = recorder_id
+
+    # Record history
+    if old_recorder_modem != modem_id:
+        record_history(db, recorder_id, "update", "deployed_with_modem_id",
+                      old_recorder_modem, modem_id, "pair_devices", f"Paired with modem")
+    if old_modem_unit != recorder_id:
+        record_history(db, modem_id, "update", "deployed_with_unit_id",
+                      old_modem_unit, recorder_id, "pair_devices", f"Paired with recorder")
+
+    db.commit()
+
+    logger.info(f"Paired {recorder_id} with modem {modem_id}")
+
+    # If SLM, sync to SLMM cache
+    if recorder.device_type == "slm":
+        await sync_slm_to_slmm_cache(
+            unit_id=recorder_id,
+            host=recorder.slm_host,
+            tcp_port=recorder.slm_tcp_port,
+            ftp_port=recorder.slm_ftp_port,
+            deployed_with_modem_id=modem_id,
+            db=db
+        )
+
+    return {
+        "success": True,
+        "message": f"Paired {recorder_id} with {modem_id}",
+        "recorder_id": recorder_id,
+        "modem_id": modem_id
+    }
+
+
+@router.post("/unpair-devices")
+async def unpair_devices(
+    request: Request,
+    db: Session = Depends(get_db)
+):
+    """
+    Remove the bidirectional pairing between a recorder and modem.
+
+    Clears:
+    - recorder.deployed_with_modem_id
+    - modem.deployed_with_unit_id
+    """
+    data = await request.json()
+    recorder_id = data.get("recorder_id")
+    modem_id = data.get("modem_id")
+
+    if not recorder_id or not modem_id:
+        raise HTTPException(status_code=400, detail="Both recorder_id and modem_id are required")
+
+    recorder = db.query(RosterUnit).filter(RosterUnit.id == recorder_id).first()
+    modem = db.query(RosterUnit).filter(RosterUnit.id == modem_id).first()
+
+    changes_made = False
+
+    if recorder and recorder.deployed_with_modem_id == modem_id:
+        record_history(db, recorder_id, "update", "deployed_with_modem_id",
+                      recorder.deployed_with_modem_id, None, "unpair_devices", "Unpairing")
+        recorder.deployed_with_modem_id = None
+        changes_made = True
+
+    if modem and modem.deployed_with_unit_id == recorder_id:
+        record_history(db, modem_id, "update", "deployed_with_unit_id",
+                      modem.deployed_with_unit_id, None, "unpair_devices", "Unpairing")
+        modem.deployed_with_unit_id = None
+        changes_made = True
+
+    if changes_made:
+        db.commit()
+        logger.info(f"Unpaired {recorder_id} from modem {modem_id}")
+        return {
+            "success": True,
+            "message": f"Unpaired {recorder_id} from {modem_id}"
+        }
+    else:
+        return {
+            "success": False,
+            "message": "No pairing found between these devices"
+        }

backend/routers/slm_dashboard.py

@@ -167,23 +167,7 @@ async def get_live_view(request: Request, unit_id: str, db: Session = Depends(ge
                 measurement_state = state_data.get("measurement_state", "Unknown")
                 is_measuring = state_data.get("is_measuring", False)
 
-            # If measuring, sync start time from FTP to database (fixes wrong timestamps)
+            # Get live status (measurement_start_time is already stored in SLMM database)
-            if is_measuring:
-                try:
-                    sync_response = await client.post(
-                        f"{SLMM_BASE_URL}/api/nl43/{unit_id}/sync-start-time",
-                        timeout=10.0
-                    )
-                    if sync_response.status_code == 200:
-                        sync_data = sync_response.json()
-                        logger.info(f"Synced start time for {unit_id}: {sync_data.get('message')}")
-                    else:
-                        logger.warning(f"Failed to sync start time for {unit_id}: {sync_response.status_code}")
-                except Exception as e:
-                    # Don't fail the whole request if sync fails
-                    logger.warning(f"Could not sync start time for {unit_id}: {e}")
-
-            # Get live status (now with corrected start time)
             status_response = await client.get(
                 f"{SLMM_BASE_URL}/api/nl43/{unit_id}/live"
             )

backend/services/device_controller.py

@@ -289,6 +289,74 @@ class DeviceController:
         else:
             raise UnsupportedDeviceTypeError(f"Unsupported device type: {device_type}")
 
+    # ========================================================================
+    # FTP Control
+    # ========================================================================
+
+    async def enable_ftp(
+        self,
+        unit_id: str,
+        device_type: str,
+    ) -> Dict[str, Any]:
+        """
+        Enable FTP server on device.
+
+        Must be called before downloading files.
+
+        Args:
+            unit_id: Unit identifier
+            device_type: "slm" | "seismograph"
+
+        Returns:
+            Response dict with status
+        """
+        if device_type == "slm":
+            try:
+                return await self.slmm_client.enable_ftp(unit_id)
+            except SLMMClientError as e:
+                raise DeviceControllerError(f"SLMM error: {str(e)}")
+
+        elif device_type == "seismograph":
+            return {
+                "status": "not_implemented",
+                "message": "Seismograph FTP not yet implemented",
+                "unit_id": unit_id,
+            }
+
+        else:
+            raise UnsupportedDeviceTypeError(f"Unsupported device type: {device_type}")
+
+    async def disable_ftp(
+        self,
+        unit_id: str,
+        device_type: str,
+    ) -> Dict[str, Any]:
+        """
+        Disable FTP server on device.
+
+        Args:
+            unit_id: Unit identifier
+            device_type: "slm" | "seismograph"
+
+        Returns:
+            Response dict with status
+        """
+        if device_type == "slm":
+            try:
+                return await self.slmm_client.disable_ftp(unit_id)
+            except SLMMClientError as e:
+                raise DeviceControllerError(f"SLMM error: {str(e)}")
+
+        elif device_type == "seismograph":
+            return {
+                "status": "not_implemented",
+                "message": "Seismograph FTP not yet implemented",
+                "unit_id": unit_id,
+            }
+
+        else:
+            raise UnsupportedDeviceTypeError(f"Unsupported device type: {device_type}")
+
     # ========================================================================
     # Device Configuration
     # ========================================================================

backend/services/scheduler.py

@@ -350,7 +350,14 @@ class SchedulerService:
         unit_id: str,
         db: Session,
     ) -> Dict[str, Any]:
-        """Execute a 'download' action."""
+        """Execute a 'download' action.
+
+        This handles standalone download actions (not part of stop_cycle).
+        The workflow is:
+        1. Enable FTP on device
+        2. Download current measurement folder
+        3. (Optionally disable FTP - left enabled for now)
+        """
         # Get project and location info for file path
         location = db.query(MonitoringLocation).filter_by(id=action.location_id).first()
         project = db.query(Project).filter_by(id=action.project_id).first()
@@ -358,8 +365,8 @@ class SchedulerService:
         if not location or not project:
             raise Exception("Project or location not found")
 
-        # Build destination path
+        # Build destination path (for logging/metadata reference)
-        # Example: data/Projects/{project-id}/sound/{location-name}/session-{timestamp}/
+        # Actual download location is managed by SLMM (data/downloads/{unit_id}/)
         session_timestamp = datetime.utcnow().strftime("%Y-%m-%d-%H%M")
         location_type_dir = "sound" if action.device_type == "slm" else "vibration"
 
@@ -368,12 +375,18 @@ class SchedulerService:
             f"{location.name}/session-{session_timestamp}/"
         )
 
-        # Download files via device controller
+        # Step 1: Enable FTP on device
+        logger.info(f"Enabling FTP on {unit_id} for download")
+        await self.device_controller.enable_ftp(unit_id, action.device_type)
+
+        # Step 2: Download current measurement folder
+        # The slmm_client.download_files() now automatically determines the correct
+        # folder based on the device's current index number
         response = await self.device_controller.download_files(
             unit_id,
             action.device_type,
             destination_path,
-            files=None,  # Download all files
+            files=None,  # Download all files in current measurement folder
         )
 
         # TODO: Create DataFile records for downloaded files

backend/services/slm_status_sync.py

@@ -0,0 +1,125 @@
+"""
+SLM Status Synchronization Service
+
+Syncs SLM device status from SLMM backend to Terra-View's Emitter table.
+This bridges SLMM's polling data with Terra-View's status snapshot system.
+
+SLMM tracks device reachability via background polling. This service
+fetches that data and creates/updates Emitter records so SLMs appear
+correctly in the dashboard status snapshot.
+"""
+
+import logging
+from datetime import datetime, timezone
+from typing import Dict, Any
+
+from backend.database import get_db_session
+from backend.models import Emitter
+from backend.services.slmm_client import get_slmm_client, SLMMClientError
+
+logger = logging.getLogger(__name__)
+
+
+async def sync_slm_status_to_emitters() -> Dict[str, Any]:
+    """
+    Fetch SLM status from SLMM and sync to Terra-View's Emitter table.
+
+    For each device in SLMM's polling status:
+    - If last_success exists, create/update Emitter with that timestamp
+    - If not reachable, update Emitter with last known timestamp (or None)
+
+    Returns:
+        Dict with synced_count, error_count, errors list
+    """
+    client = get_slmm_client()
+    synced = 0
+    errors = []
+
+    try:
+        # Get polling status from SLMM
+        status_response = await client.get_polling_status()
+
+        # Handle nested response structure
+        data = status_response.get("data", status_response)
+        devices = data.get("devices", [])
+
+        if not devices:
+            logger.debug("No SLM devices in SLMM polling status")
+            return {"synced_count": 0, "error_count": 0, "errors": []}
+
+        db = get_db_session()
+        try:
+            for device in devices:
+                unit_id = device.get("unit_id")
+                if not unit_id:
+                    continue
+
+                try:
+                    # Get or create Emitter record
+                    emitter = db.query(Emitter).filter(Emitter.id == unit_id).first()
+
+                    # Determine last_seen from SLMM data
+                    last_success_str = device.get("last_success")
+                    is_reachable = device.get("is_reachable", False)
+
+                    if last_success_str:
+                        # Parse ISO format timestamp
+                        last_seen = datetime.fromisoformat(
+                            last_success_str.replace("Z", "+00:00")
+                        )
+                        # Convert to naive UTC for consistency with existing code
+                        if last_seen.tzinfo:
+                            last_seen = last_seen.astimezone(timezone.utc).replace(tzinfo=None)
+                    else:
+                        last_seen = None
+
+                    # Status will be recalculated by snapshot.py based on time thresholds
+                    # Just store a provisional status here
+                    status = "OK" if is_reachable else "Missing"
+
+                    # Store last error message if available
+                    last_error = device.get("last_error") or ""
+
+                    if emitter:
+                        # Update existing record
+                        emitter.last_seen = last_seen
+                        emitter.status = status
+                        emitter.unit_type = "slm"
+                        emitter.last_file = last_error
+                    else:
+                        # Create new record
+                        emitter = Emitter(
+                            id=unit_id,
+                            unit_type="slm",
+                            last_seen=last_seen,
+                            last_file=last_error,
+                            status=status
+                        )
+                        db.add(emitter)
+
+                    synced += 1
+
+                except Exception as e:
+                    errors.append(f"{unit_id}: {str(e)}")
+                    logger.error(f"Error syncing SLM {unit_id}: {e}")
+
+            db.commit()
+
+        finally:
+            db.close()
+
+        if synced > 0:
+            logger.info(f"Synced {synced} SLM device(s) to Emitter table")
+
+    except SLMMClientError as e:
+        logger.warning(f"Could not reach SLMM for status sync: {e}")
+        errors.append(f"SLMM unreachable: {str(e)}")
+    except Exception as e:
+        logger.error(f"Error in SLM status sync: {e}", exc_info=True)
+        errors.append(str(e))
+
+    return {
+        "synced_count": synced,
+        "error_count": len(errors),
+        "errors": errors
+    }

backend/services/slmm_client.py

@@ -478,9 +478,118 @@ class SLMMClient:
         return await self._request("GET", f"/{unit_id}/settings")
 
     # ========================================================================
-    # Data Download (Future)
+    # FTP Control
     # ========================================================================
 
+    async def enable_ftp(self, unit_id: str) -> Dict[str, Any]:
+        """
+        Enable FTP server on device.
+
+        Must be called before downloading files. FTP and TCP can work in tandem.
+
+        Args:
+            unit_id: Unit identifier
+
+        Returns:
+            Dict with status message
+        """
+        return await self._request("POST", f"/{unit_id}/ftp/enable")
+
+    async def disable_ftp(self, unit_id: str) -> Dict[str, Any]:
+        """
+        Disable FTP server on device.
+
+        Args:
+            unit_id: Unit identifier
+
+        Returns:
+            Dict with status message
+        """
+        return await self._request("POST", f"/{unit_id}/ftp/disable")
+
+    async def get_ftp_status(self, unit_id: str) -> Dict[str, Any]:
+        """
+        Get FTP server status on device.
+
+        Args:
+            unit_id: Unit identifier
+
+        Returns:
+            Dict with ftp_enabled status
+        """
+        return await self._request("GET", f"/{unit_id}/ftp/status")
+
+    # ========================================================================
+    # Data Download
+    # ========================================================================
+
+    async def download_file(
+        self,
+        unit_id: str,
+        remote_path: str,
+    ) -> Dict[str, Any]:
+        """
+        Download a single file from unit via FTP.
+
+        Args:
+            unit_id: Unit identifier
+            remote_path: Path on device to download (e.g., "/NL43_DATA/measurement.wav")
+
+        Returns:
+            Binary file content (as response)
+        """
+        data = {"remote_path": remote_path}
+        return await self._request("POST", f"/{unit_id}/ftp/download", data=data)
+
+    async def download_folder(
+        self,
+        unit_id: str,
+        remote_path: str,
+    ) -> Dict[str, Any]:
+        """
+        Download an entire folder from unit via FTP as a ZIP archive.
+
+        Useful for downloading complete measurement sessions (e.g., Auto_0000 folders).
+
+        Args:
+            unit_id: Unit identifier
+            remote_path: Folder path on device to download (e.g., "/NL43_DATA/Auto_0000")
+
+        Returns:
+            Dict with local_path, folder_name, file_count, zip_size_bytes
+        """
+        data = {"remote_path": remote_path}
+        return await self._request("POST", f"/{unit_id}/ftp/download-folder", data=data)
+
+    async def download_current_measurement(
+        self,
+        unit_id: str,
+    ) -> Dict[str, Any]:
+        """
+        Download the current measurement folder based on device's index number.
+
+        This is the recommended method for scheduled downloads - it automatically
+        determines which folder to download based on the device's current store index.
+
+        Args:
+            unit_id: Unit identifier
+
+        Returns:
+            Dict with local_path, folder_name, file_count, zip_size_bytes, index_number
+        """
+        # Get current index number from device
+        index_info = await self.get_index_number(unit_id)
+        index_number = index_info.get("index_number", 0)
+
+        # Format as Auto_XXXX folder name
+        folder_name = f"Auto_{index_number:04d}"
+        remote_path = f"/NL43_DATA/{folder_name}"
+
+        # Download the folder
+        result = await self.download_folder(unit_id, remote_path)
+        result["index_number"] = index_number
+        return result
+
     async def download_files(
         self,
         unit_id: str,
@@ -488,23 +597,24 @@ class SLMMClient:
         files: Optional[List[str]] = None,
     ) -> Dict[str, Any]:
         """
-        Download files from unit via FTP.
+        Download measurement files from unit via FTP.
 
-        NOTE: This endpoint doesn't exist in SLMM yet. Will need to implement.
+        This method automatically determines the current measurement folder and downloads it.
+        The destination_path parameter is logged for reference but actual download location
+        is managed by SLMM (data/downloads/{unit_id}/).
 
         Args:
             unit_id: Unit identifier
-            destination_path: Local path to save files
+            destination_path: Reference path (for logging/metadata, not used by SLMM)
-            files: List of filenames to download, or None for all
+            files: Ignored - always downloads the current measurement folder
 
         Returns:
-            Dict with downloaded files list and metadata
+            Dict with download result including local_path, folder_name, etc.
         """
-        data = {
+        # Use the new method that automatically determines what to download
-            "destination_path": destination_path,
+        result = await self.download_current_measurement(unit_id)
-            "files": files or "all",
+        result["requested_destination"] = destination_path
-        }
+        return result
-        return await self._request("POST", f"/{unit_id}/ftp/download", data=data)
 
     # ========================================================================
     # Cycle Commands (for scheduled automation)

backend/services/slmm_sync.py

@@ -36,6 +36,10 @@ async def sync_slm_to_slmm(unit: RosterUnit) -> bool:
         logger.warning(f"SLM {unit.id} has no host configured, skipping SLMM sync")
         return False
 
+    # Disable polling if unit is benched (deployed=False) or retired
+    # Only actively deployed units should be polled
+    should_poll = unit.deployed and not unit.retired
+
     try:
         async with httpx.AsyncClient(timeout=5.0) as client:
             response = await client.put(
@@ -47,8 +51,8 @@ async def sync_slm_to_slmm(unit: RosterUnit) -> bool:
                     "ftp_enabled": True,
                     "ftp_username": "USER",  # Default NL43 credentials
                     "ftp_password": "0000",
-                    "poll_enabled": not unit.retired,  # Disable polling for retired units
+                    "poll_enabled": should_poll,  # Disable polling for benched or retired units
-                    "poll_interval_seconds": 60,  # Default interval
+                    "poll_interval_seconds": 3600,  # Default to 1 hour polling
                 }
             )
 

backend/services/snapshot.py

@@ -108,6 +108,7 @@ def emit_status_snapshot():
                 "last_calibrated": r.last_calibrated.isoformat() if r.last_calibrated else None,
                 "next_calibration_due": r.next_calibration_due.isoformat() if r.next_calibration_due else None,
                 "deployed_with_modem_id": r.deployed_with_modem_id,
+                "deployed_with_unit_id": r.deployed_with_unit_id,
                 "ip_address": r.ip_address,
                 "phone_number": r.phone_number,
                     "hardware_model": r.hardware_model,
@@ -137,6 +138,7 @@ def emit_status_snapshot():
                     "last_calibrated": None,
                     "next_calibration_due": None,
                     "deployed_with_modem_id": None,
+                    "deployed_with_unit_id": None,
                     "ip_address": None,
                     "phone_number": None,
                     "hardware_model": None,
@@ -146,6 +148,34 @@ def emit_status_snapshot():
                     "coordinates": "",
                 }
 
+        # --- Derive modem status from paired devices ---
+        # Modems don't have their own check-in system, so we inherit status
+        # from whatever device they're paired with (seismograph or SLM)
+        # Check both directions: modem.deployed_with_unit_id OR device.deployed_with_modem_id
+        for unit_id, unit_data in units.items():
+            if unit_data.get("device_type") == "modem" and not unit_data.get("retired"):
+                paired_unit_id = None
+                roster_unit = roster.get(unit_id)
+
+                # First, check if modem has deployed_with_unit_id set
+                if roster_unit and roster_unit.deployed_with_unit_id:
+                    paired_unit_id = roster_unit.deployed_with_unit_id
+                else:
+                    # Fallback: check if any device has this modem in deployed_with_modem_id
+                    for other_id, other_roster in roster.items():
+                        if other_roster.deployed_with_modem_id == unit_id:
+                            paired_unit_id = other_id
+                            break
+
+                if paired_unit_id:
+                    paired_unit = units.get(paired_unit_id)
+                    if paired_unit:
+                        # Inherit status from paired device
+                        unit_data["status"] = paired_unit.get("status", "Missing")
+                        unit_data["age"] = paired_unit.get("age", "N/A")
+                        unit_data["last"] = paired_unit.get("last")
+                        unit_data["derived_from"] = paired_unit_id
+
         # Separate buckets for UI
         active_units = {
             uid: u for uid, u in units.items()

templates/base.html

@@ -137,6 +137,13 @@
                     Modems
                 </a>
 
+                <a href="/pair-devices" class="flex items-center px-4 py-3 rounded-lg hover:bg-gray-100 dark:hover:bg-gray-700 {% if request.url.path == '/pair-devices' %}bg-gray-100 dark:bg-gray-700{% endif %}">
+                    <svg class="w-5 h-5 mr-3" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                        <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M13.828 10.172a4 4 0 00-5.656 0l-4 4a4 4 0 105.656 5.656l1.102-1.101m-.758-4.899a4 4 0 005.656 0l4-4a4 4 0 00-5.656-5.656l-1.1 1.1"></path>
+                    </svg>
+                    Pair Devices
+                </a>
+
                 <a href="/projects" class="flex items-center px-4 py-3 rounded-lg hover:bg-gray-100 dark:hover:bg-gray-700 {% if request.url.path.startswith('/projects') %}bg-gray-100 dark:bg-gray-700{% endif %}">
                     <svg class="w-5 h-5 mr-3" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                         <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M19 11H5m14 0a2 2 0 012 2v6a2 2 0 01-2 2H5a2 2 0 01-2-2v-6a2 2 0 012-2m14 0V9a2 2 0 00-2-2M5 11V9a2 2 0 012-2m0 0V5a2 2 0 012-2h6a2 2 0 012 2v2M7 7h10"></path>

templates/dashboard.html

@@ -187,6 +187,68 @@
 
     </div>
 
+    <!-- Dashboard Filters -->
+    <div class="rounded-xl shadow-lg bg-white dark:bg-slate-700 p-4 mb-4" id="dashboard-filters-card">
+        <div class="flex items-center justify-between mb-3">
+            <h3 class="text-sm font-semibold text-gray-700 dark:text-gray-300">Filter Dashboard</h3>
+            <button onclick="resetFilters()" class="text-xs text-gray-500 hover:text-seismo-orange dark:hover:text-seismo-orange transition-colors">
+                Reset Filters
+            </button>
+        </div>
+
+        <div class="flex flex-wrap gap-6">
+            <!-- Device Type Filters -->
+            <div class="flex flex-col gap-1">
+                <span class="text-xs text-gray-500 dark:text-gray-400 font-medium uppercase tracking-wide">Device Type</span>
+                <div class="flex gap-4">
+                    <label class="flex items-center gap-1.5 cursor-pointer">
+                        <input type="checkbox" id="filter-seismograph" checked
+                               class="rounded border-gray-300 text-blue-600 focus:ring-blue-500 dark:border-gray-600 dark:bg-slate-800"
+                               onchange="applyFilters()">
+                        <span class="text-sm text-gray-700 dark:text-gray-300">Seismographs</span>
+                    </label>
+                    <label class="flex items-center gap-1.5 cursor-pointer">
+                        <input type="checkbox" id="filter-slm" checked
+                               class="rounded border-gray-300 text-purple-600 focus:ring-purple-500 dark:border-gray-600 dark:bg-slate-800"
+                               onchange="applyFilters()">
+                        <span class="text-sm text-gray-700 dark:text-gray-300">SLMs</span>
+                    </label>
+                    <label class="flex items-center gap-1.5 cursor-pointer">
+                        <input type="checkbox" id="filter-modem" checked
+                               class="rounded border-gray-300 text-cyan-600 focus:ring-cyan-500 dark:border-gray-600 dark:bg-slate-800"
+                               onchange="applyFilters()">
+                        <span class="text-sm text-gray-700 dark:text-gray-300">Modems</span>
+                    </label>
+                </div>
+            </div>
+
+            <!-- Status Filters -->
+            <div class="flex flex-col gap-1">
+                <span class="text-xs text-gray-500 dark:text-gray-400 font-medium uppercase tracking-wide">Status</span>
+                <div class="flex gap-4">
+                    <label class="flex items-center gap-1.5 cursor-pointer">
+                        <input type="checkbox" id="filter-ok" checked
+                               class="rounded border-gray-300 text-green-600 focus:ring-green-500 dark:border-gray-600 dark:bg-slate-800"
+                               onchange="applyFilters()">
+                        <span class="text-sm text-green-600 dark:text-green-400">OK</span>
+                    </label>
+                    <label class="flex items-center gap-1.5 cursor-pointer">
+                        <input type="checkbox" id="filter-pending" checked
+                               class="rounded border-gray-300 text-yellow-600 focus:ring-yellow-500 dark:border-gray-600 dark:bg-slate-800"
+                               onchange="applyFilters()">
+                        <span class="text-sm text-yellow-600 dark:text-yellow-400">Pending</span>
+                    </label>
+                    <label class="flex items-center gap-1.5 cursor-pointer">
+                        <input type="checkbox" id="filter-missing" checked
+                               class="rounded border-gray-300 text-red-600 focus:ring-red-500 dark:border-gray-600 dark:bg-slate-800"
+                               onchange="applyFilters()">
+                        <span class="text-sm text-red-600 dark:text-red-400">Missing</span>
+                    </label>
+                </div>
+            </div>
+        </div>
+    </div>
+
     <!-- Fleet Map -->
     <div class="rounded-xl shadow-lg bg-white dark:bg-slate-700 p-6 mb-8" id="fleet-map-card">
         <div class="flex items-center justify-between mb-4 cursor-pointer md:cursor-default" onclick="toggleCard('fleet-map')">
@@ -302,6 +364,254 @@
 
 
 <script>
+// ===== Dashboard Filtering System =====
+let currentSnapshotData = null;  // Store latest snapshot data for re-filtering
+
+// Filter state - tracks which device types and statuses to show
+const filters = {
+    deviceTypes: {
+        seismograph: true,
+        sound_level_meter: true,
+        modem: true
+    },
+    statuses: {
+        OK: true,
+        Pending: true,
+        Missing: true
+    }
+};
+
+// Load saved filter preferences from localStorage
+function loadFilterPreferences() {
+    const saved = localStorage.getItem('dashboardFilters');
+    if (saved) {
+        try {
+            const parsed = JSON.parse(saved);
+            if (parsed.deviceTypes) Object.assign(filters.deviceTypes, parsed.deviceTypes);
+            if (parsed.statuses) Object.assign(filters.statuses, parsed.statuses);
+        } catch (e) {
+            console.error('Error loading filter preferences:', e);
+        }
+    }
+
+    // Sync checkboxes with loaded state
+    const seismoCheck = document.getElementById('filter-seismograph');
+    const slmCheck = document.getElementById('filter-slm');
+    const modemCheck = document.getElementById('filter-modem');
+    const okCheck = document.getElementById('filter-ok');
+    const pendingCheck = document.getElementById('filter-pending');
+    const missingCheck = document.getElementById('filter-missing');
+
+    if (seismoCheck) seismoCheck.checked = filters.deviceTypes.seismograph;
+    if (slmCheck) slmCheck.checked = filters.deviceTypes.sound_level_meter;
+    if (modemCheck) modemCheck.checked = filters.deviceTypes.modem;
+    if (okCheck) okCheck.checked = filters.statuses.OK;
+    if (pendingCheck) pendingCheck.checked = filters.statuses.Pending;
+    if (missingCheck) missingCheck.checked = filters.statuses.Missing;
+}
+
+// Save filter preferences to localStorage
+function saveFilterPreferences() {
+    localStorage.setItem('dashboardFilters', JSON.stringify(filters));
+}
+
+// Apply filters - called when any checkbox changes
+function applyFilters() {
+    // Update filter state from checkboxes
+    const seismoCheck = document.getElementById('filter-seismograph');
+    const slmCheck = document.getElementById('filter-slm');
+    const modemCheck = document.getElementById('filter-modem');
+    const okCheck = document.getElementById('filter-ok');
+    const pendingCheck = document.getElementById('filter-pending');
+    const missingCheck = document.getElementById('filter-missing');
+
+    if (seismoCheck) filters.deviceTypes.seismograph = seismoCheck.checked;
+    if (slmCheck) filters.deviceTypes.sound_level_meter = slmCheck.checked;
+    if (modemCheck) filters.deviceTypes.modem = modemCheck.checked;
+    if (okCheck) filters.statuses.OK = okCheck.checked;
+    if (pendingCheck) filters.statuses.Pending = pendingCheck.checked;
+    if (missingCheck) filters.statuses.Missing = missingCheck.checked;
+
+    saveFilterPreferences();
+
+    // Re-render with current data and filters
+    if (currentSnapshotData) {
+        renderFilteredDashboard(currentSnapshotData);
+    }
+}
+
+// Reset all filters to show everything
+function resetFilters() {
+    filters.deviceTypes = { seismograph: true, sound_level_meter: true, modem: true };
+    filters.statuses = { OK: true, Pending: true, Missing: true };
+
+    // Update all checkboxes
+    const checkboxes = [
+        'filter-seismograph', 'filter-slm', 'filter-modem',
+        'filter-ok', 'filter-pending', 'filter-missing'
+    ];
+    checkboxes.forEach(id => {
+        const el = document.getElementById(id);
+        if (el) el.checked = true;
+    });
+
+    saveFilterPreferences();
+
+    if (currentSnapshotData) {
+        renderFilteredDashboard(currentSnapshotData);
+    }
+}
+
+// Check if a unit passes the current filters
+function unitPassesFilter(unit) {
+    const deviceType = unit.device_type || 'seismograph';
+    const status = unit.status || 'Missing';
+
+    // Check device type filter
+    if (!filters.deviceTypes[deviceType]) {
+        return false;
+    }
+
+    // Check status filter
+    if (!filters.statuses[status]) {
+        return false;
+    }
+
+    return true;
+}
+
+// Get display label for device type
+function getDeviceTypeLabel(deviceType) {
+    switch(deviceType) {
+        case 'sound_level_meter': return 'SLM';
+        case 'modem': return 'Modem';
+        default: return 'Seismograph';
+    }
+}
+
+// Render dashboard with filtered data
+function renderFilteredDashboard(data) {
+    // Filter active units for alerts
+    const filteredActive = {};
+    Object.entries(data.active || {}).forEach(([id, unit]) => {
+        if (unitPassesFilter(unit)) {
+            filteredActive[id] = unit;
+        }
+    });
+
+    // Update alerts with filtered data
+    updateAlertsFiltered(filteredActive);
+
+    // Update map with filtered data
+    updateFleetMapFiltered(data.units);
+}
+
+// Update the Recent Alerts section with filtering
+function updateAlertsFiltered(filteredActive) {
+    const alertsList = document.getElementById('alerts-list');
+    const missingUnits = Object.entries(filteredActive).filter(([_, u]) => u.status === 'Missing');
+
+    if (!missingUnits.length) {
+        // Check if this is because of filters or genuinely no alerts
+        const anyMissing = currentSnapshotData && Object.values(currentSnapshotData.active || {}).some(u => u.status === 'Missing');
+        if (anyMissing) {
+            alertsList.innerHTML = '<p class="text-sm text-gray-500 dark:text-gray-400">No alerts match current filters</p>';
+        } else {
+            alertsList.innerHTML = '<p class="text-sm text-green-600 dark:text-green-400">All units reporting normally</p>';
+        }
+    } else {
+        let alertsHtml = '';
+        missingUnits.forEach(([id, unit]) => {
+            const deviceLabel = getDeviceTypeLabel(unit.device_type);
+            alertsHtml += `
+            <div class="flex items-start space-x-2 text-sm">
+                <span class="w-2 h-2 rounded-full bg-red-500 mt-1.5"></span>
+                <div>
+                    <a href="/unit/${id}" class="font-medium text-red-600 dark:text-red-400 hover:underline">${id}</a>
+                    <span class="text-xs text-gray-500 ml-1">(${deviceLabel})</span>
+                    <p class="text-gray-600 dark:text-gray-400">Missing for ${unit.age}</p>
+                </div>
+            </div>`;
+        });
+        alertsList.innerHTML = alertsHtml;
+    }
+}
+
+// Update map with filtered data
+function updateFleetMapFiltered(allUnits) {
+    if (!fleetMap) return;
+
+    // Clear existing markers
+    fleetMarkers.forEach(marker => fleetMap.removeLayer(marker));
+    fleetMarkers = [];
+
+    // Get deployed units with coordinates that pass the filter
+    const deployedUnits = Object.entries(allUnits || {})
+        .filter(([_, u]) => u.deployed && u.coordinates && unitPassesFilter(u));
+
+    if (deployedUnits.length === 0) {
+        return;
+    }
+
+    const bounds = [];
+
+    deployedUnits.forEach(([id, unit]) => {
+        const coords = parseLocation(unit.coordinates);
+        if (coords) {
+            const [lat, lon] = coords;
+
+            // Color based on status
+            const markerColor = unit.status === 'OK' ? 'green' :
+                               unit.status === 'Pending' ? 'orange' : 'red';
+
+            // Different marker style per device type
+            const deviceType = unit.device_type || 'seismograph';
+            let radius = 8;
+            let weight = 2;
+
+            if (deviceType === 'modem') {
+                radius = 6;
+                weight = 2;
+            } else if (deviceType === 'sound_level_meter') {
+                radius = 8;
+                weight = 3;
+            }
+
+            const marker = L.circleMarker([lat, lon], {
+                radius: radius,
+                fillColor: markerColor,
+                color: '#fff',
+                weight: weight,
+                opacity: 1,
+                fillOpacity: 0.8
+            }).addTo(fleetMap);
+
+            // Popup with device type
+            const deviceLabel = getDeviceTypeLabel(deviceType);
+
+            marker.bindPopup(`
+                <div class="p-2">
+                    <h3 class="font-bold text-lg">${id}</h3>
+                    <p class="text-sm text-gray-600">${deviceLabel}</p>
+                    <p class="text-sm">Status: <span style="color: ${markerColor}">${unit.status}</span></p>
+                    ${unit.note ? `<p class="text-sm text-gray-600">${unit.note}</p>` : ''}
+                    <a href="/unit/${id}" class="text-blue-600 hover:underline text-sm">View Details</a>
+                </div>
+            `);
+
+            fleetMarkers.push(marker);
+            bounds.push([lat, lon]);
+        }
+    });
+
+    // Fit bounds if we have markers
+    if (bounds.length > 0) {
+        const padding = window.innerWidth < 768 ? [20, 20] : [50, 50];
+        fleetMap.fitBounds(bounds, { padding: padding });
+        fleetMapInitialized = true;
+    }
+}
+
 // Toggle card collapse/expand (mobile only)
 function toggleCard(cardName) {
     // Only work on mobile
@@ -366,8 +676,17 @@ if (document.readyState === 'loading') {
 
 function updateDashboard(event) {
     try {
+        // Only process responses from /api/status-snapshot
+        const requestUrl = event.detail.xhr.responseURL || event.detail.pathInfo?.requestPath;
+        if (!requestUrl || !requestUrl.includes('/api/status-snapshot')) {
+            return; // Ignore responses from other endpoints (like /dashboard/todays-actions)
+        }
+
         const data = JSON.parse(event.detail.xhr.response);
 
+        // Store data for filter re-application
+        currentSnapshotData = data;
+
         // Update "Last updated" timestamp with timezone
         const now = new Date();
         const timezone = localStorage.getItem('timezone') || 'America/New_York';
@@ -379,7 +698,7 @@ function updateDashboard(event) {
             timeZoneName: 'short'
         });
 
-        // ===== Fleet summary numbers =====
+        // ===== Fleet summary numbers (always unfiltered) =====
         document.getElementById('total-units').textContent = data.summary?.total ?? 0;
         document.getElementById('deployed-units').textContent = data.summary?.active ?? 0;
         document.getElementById('benched-units').textContent = data.summary?.benched ?? 0;
@@ -387,9 +706,10 @@ function updateDashboard(event) {
         document.getElementById('status-pending').textContent = data.summary?.pending ?? 0;
         document.getElementById('status-missing').textContent = data.summary?.missing ?? 0;
 
-        // ===== Device type counts =====
+        // ===== Device type counts (always unfiltered) =====
         let seismoCount = 0;
         let slmCount = 0;
+        let modemCount = 0;
         Object.values(data.units || {}).forEach(unit => {
             if (unit.retired) return; // Don't count retired units
             const deviceType = unit.device_type || 'seismograph';
@@ -397,46 +717,26 @@ function updateDashboard(event) {
                 seismoCount++;
             } else if (deviceType === 'sound_level_meter') {
                 slmCount++;
+            } else if (deviceType === 'modem') {
+                modemCount++;
             }
         });
         document.getElementById('seismo-count').textContent = seismoCount;
         document.getElementById('slm-count').textContent = slmCount;
 
-        // ===== Alerts =====
+        // ===== Apply filters and render map + alerts =====
-        const alertsList = document.getElementById('alerts-list');
+        renderFilteredDashboard(data);
-        // Only show alerts for deployed units that are MISSING (not pending)
-        const missingUnits = Object.entries(data.active).filter(([_, u]) => u.status === 'Missing');
-
-        if (!missingUnits.length) {
-            alertsList.innerHTML =
-                '<p class="text-sm text-green-600 dark:text-green-400">✓ All units reporting normally</p>';
-        } else {
-            let alertsHtml = '';
-
-            missingUnits.forEach(([id, unit]) => {
-                alertsHtml += `
-                <div class="flex items-start space-x-2 text-sm">
-                    <span class="w-2 h-2 rounded-full bg-red-500 mt-1.5"></span>
-                    <div>
-                        <a href="/unit/${id}" class="font-medium text-red-600 dark:text-red-400 hover:underline">${id}</a>
-                        <p class="text-gray-600 dark:text-gray-400">Missing for ${unit.age}</p>
-                    </div>
-                </div>`;
-            });
-
-            alertsList.innerHTML = alertsHtml;
-        }
-
-        // ===== Update Fleet Map =====
-        updateFleetMap(data);
 
     } catch (err) {
         console.error("Dashboard update error:", err);
     }
 }
 
-// Handle tab switching
+// Handle tab switching and initialize components
 document.addEventListener('DOMContentLoaded', function() {
+    // Load filter preferences
+    loadFilterPreferences();
+
     const tabButtons = document.querySelectorAll('.tab-button');
 
     tabButtons.forEach(button => {
@@ -476,64 +776,6 @@ function initFleetMap() {
     }, 100);
 }
 
-function updateFleetMap(data) {
-    if (!fleetMap) return;
-
-    // Clear existing markers
-    fleetMarkers.forEach(marker => fleetMap.removeLayer(marker));
-    fleetMarkers = [];
-
-    // Get deployed units with coordinates data
-    const deployedUnits = Object.entries(data.units).filter(([_, u]) => u.deployed && u.coordinates);
-
-    if (deployedUnits.length === 0) {
-        return;
-    }
-
-    const bounds = [];
-
-    deployedUnits.forEach(([id, unit]) => {
-        const coords = parseLocation(unit.coordinates);
-        if (coords) {
-            const [lat, lon] = coords;
-
-            // Create marker with custom color based on status
-            const markerColor = unit.status === 'OK' ? 'green' : unit.status === 'Pending' ? 'orange' : 'red';
-
-            const marker = L.circleMarker([lat, lon], {
-                radius: 8,
-                fillColor: markerColor,
-                color: '#fff',
-                weight: 2,
-                opacity: 1,
-                fillOpacity: 0.8
-            }).addTo(fleetMap);
-
-            // Add popup with unit info
-            marker.bindPopup(`
-                <div class="p-2">
-                    <h3 class="font-bold text-lg">${id}</h3>
-                    <p class="text-sm">Status: <span style="color: ${markerColor}">${unit.status}</span></p>
-                    <p class="text-sm">Type: ${unit.device_type}</p>
-                    ${unit.note ? `<p class="text-sm text-gray-600">${unit.note}</p>` : ''}
-                    <a href="/unit/${id}" class="text-blue-600 hover:underline text-sm">View Details →</a>
-                </div>
-            `);
-
-            fleetMarkers.push(marker);
-            bounds.push([lat, lon]);
-        }
-    });
-
-    // Fit map to show all markers
-    if (bounds.length > 0) {
-        // Use different padding for mobile vs desktop
-        const padding = window.innerWidth < 768 ? [20, 20] : [50, 50];
-        fleetMap.fitBounds(bounds, { padding: padding });
-        fleetMapInitialized = true;
-    }
-}
-
 function parseLocation(location) {
     if (!location) return null;
 

templates/modems.html

@@ -55,13 +55,7 @@
          hx-get="/api/modem-dashboard/units"
          hx-trigger="load, every 30s"
          hx-swap="innerHTML">
-        <div class="animate-pulse space-y-4">
+        <p class="text-gray-500 dark:text-gray-400">Loading modems...</p>
-            <div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
-                <div class="bg-gray-200 dark:bg-gray-700 h-40 rounded-lg"></div>
-                <div class="bg-gray-200 dark:bg-gray-700 h-40 rounded-lg"></div>
-                <div class="bg-gray-200 dark:bg-gray-700 h-40 rounded-lg"></div>
-            </div>
-        </div>
     </div>
 </div>
 

templates/pair_devices.html

@@ -0,0 +1,566 @@
+{% extends "base.html" %}
+
+{% block title %}Pair Devices - Terra-View{% endblock %}
+
+{% block content %}
+<div class="max-w-7xl mx-auto">
+    <!-- Header -->
+    <div class="mb-6">
+        <h1 class="text-2xl font-bold text-gray-900 dark:text-white">Pair Devices</h1>
+        <p class="mt-1 text-sm text-gray-600 dark:text-gray-400">
+            Select a recorder (seismograph or SLM) and a modem to create a bidirectional pairing.
+        </p>
+    </div>
+
+    <!-- Selection Summary Bar -->
+    <div id="selection-bar" class="mb-6 p-4 bg-white dark:bg-slate-800 rounded-lg shadow border border-gray-200 dark:border-gray-700">
+        <div class="flex items-center justify-between flex-wrap gap-4">
+            <div class="flex items-center gap-6">
+                <div class="flex items-center gap-2">
+                    <span class="text-sm text-gray-600 dark:text-gray-400">Recorder:</span>
+                    <span id="selected-recorder" class="font-mono font-medium text-gray-900 dark:text-white">None selected</span>
+                </div>
+                <svg class="w-5 h-5 text-gray-400" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                    <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M14 5l7 7m0 0l-7 7m7-7H3"></path>
+                </svg>
+                <div class="flex items-center gap-2">
+                    <span class="text-sm text-gray-600 dark:text-gray-400">Modem:</span>
+                    <span id="selected-modem" class="font-mono font-medium text-gray-900 dark:text-white">None selected</span>
+                </div>
+            </div>
+            <div class="flex items-center gap-3">
+                <button id="clear-selection-btn"
+                        onclick="clearSelection()"
+                        class="px-4 py-2 text-sm font-medium text-gray-700 dark:text-gray-300 bg-gray-100 dark:bg-gray-700 rounded-lg hover:bg-gray-200 dark:hover:bg-gray-600 disabled:opacity-50 disabled:cursor-not-allowed"
+                        disabled>
+                    Clear
+                </button>
+                <button id="pair-btn"
+                        onclick="pairDevices()"
+                        class="px-4 py-2 text-sm font-medium text-white bg-seismo-orange rounded-lg hover:bg-orange-600 disabled:opacity-50 disabled:cursor-not-allowed"
+                        disabled>
+                    Pair Devices
+                </button>
+            </div>
+        </div>
+    </div>
+
+    <!-- Two Column Layout -->
+    <div class="grid grid-cols-1 lg:grid-cols-2 gap-6">
+        <!-- Left Column: Recorders (Seismographs + SLMs) -->
+        <div class="bg-white dark:bg-slate-800 rounded-lg shadow border border-gray-200 dark:border-gray-700">
+            <div class="px-4 py-3 border-b border-gray-200 dark:border-gray-700">
+                <div class="flex items-center justify-between mb-3">
+                    <h2 class="text-lg font-semibold text-gray-900 dark:text-white flex items-center gap-2">
+                        <svg class="w-5 h-5 text-seismo-orange" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 19v-6a2 2 0 00-2-2H5a2 2 0 00-2 2v6a2 2 0 002 2h2a2 2 0 002-2zm0 0V9a2 2 0 012-2h2a2 2 0 012 2v10m-6 0a2 2 0 002 2h2a2 2 0 002-2m0 0V5a2 2 0 012-2h2a2 2 0 012 2v14a2 2 0 01-2 2h-2a2 2 0 01-2-2z"></path>
+                        </svg>
+                        Recorders
+                        <span id="recorder-count" class="text-sm font-normal text-gray-500 dark:text-gray-400">({{ recorders|length }})</span>
+                    </h2>
+                </div>
+                <!-- Recorder Search & Filters -->
+                <div class="space-y-2">
+                    <input type="text" id="recorder-search" placeholder="Search by ID..."
+                           class="w-full px-3 py-2 rounded-lg border border-gray-300 dark:border-gray-600 bg-white dark:bg-slate-700 text-gray-900 dark:text-white text-sm focus:ring-2 focus:ring-seismo-orange focus:border-seismo-orange"
+                           oninput="filterRecorders()">
+                    <div class="flex items-center gap-4">
+                        <label class="flex items-center gap-2 cursor-pointer">
+                            <input type="checkbox" id="recorder-hide-paired" onchange="filterRecorders()" class="rounded border-gray-300 dark:border-gray-600 text-seismo-orange focus:ring-seismo-orange">
+                            <span class="text-xs text-gray-600 dark:text-gray-400">Hide paired</span>
+                        </label>
+                        <label class="flex items-center gap-2 cursor-pointer">
+                            <input type="checkbox" id="recorder-deployed-only" onchange="filterRecorders()" class="rounded border-gray-300 dark:border-gray-600 text-seismo-orange focus:ring-seismo-orange">
+                            <span class="text-xs text-gray-600 dark:text-gray-400">Deployed only</span>
+                        </label>
+                    </div>
+                </div>
+            </div>
+            <div class="max-h-[600px] overflow-y-auto">
+                <div id="recorders-list" class="divide-y divide-gray-200 dark:divide-gray-700">
+                    {% for unit in recorders %}
+                    <div class="device-row recorder-row p-3 hover:bg-gray-50 dark:hover:bg-gray-700/50 cursor-pointer transition-colors"
+                         data-id="{{ unit.id }}"
+                         data-deployed="{{ unit.deployed|lower }}"
+                         data-paired-with="{{ unit.deployed_with_modem_id or '' }}"
+                         data-device-type="{{ unit.device_type }}"
+                         onclick="selectRecorder('{{ unit.id }}')">
+                        <div class="flex items-center justify-between">
+                            <div class="flex items-center gap-3">
+                                <div class="w-8 h-8 rounded-full flex items-center justify-center
+                                    {% if unit.device_type == 'slm' %}bg-purple-100 dark:bg-purple-900/30 text-purple-600 dark:text-purple-400
+                                    {% else %}bg-blue-100 dark:bg-blue-900/30 text-blue-600 dark:text-blue-400{% endif %}">
+                                    {% if unit.device_type == 'slm' %}
+                                    <svg class="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                                        <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M15.536 8.464a5 5 0 010 7.072m2.828-9.9a9 9 0 010 12.728M5.586 15H4a1 1 0 01-1-1v-4a1 1 0 011-1h1.586l4.707-4.707C10.923 3.663 12 4.109 12 5v14c0 .891-1.077 1.337-1.707.707L5.586 15z"></path>
+                                    </svg>
+                                    {% else %}
+                                    <svg class="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                                        <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 19v-6a2 2 0 00-2-2H5a2 2 0 00-2 2v6a2 2 0 002 2h2a2 2 0 002-2zm0 0V9a2 2 0 012-2h2a2 2 0 012 2v10m-6 0a2 2 0 002 2h2a2 2 0 002-2m0 0V5a2 2 0 012-2h2a2 2 0 012 2v14a2 2 0 01-2 2h-2a2 2 0 01-2-2z"></path>
+                                    </svg>
+                                    {% endif %}
+                                </div>
+                                <div>
+                                    <div class="font-mono font-medium text-gray-900 dark:text-white">{{ unit.id }}</div>
+                                    <div class="text-xs text-gray-500 dark:text-gray-400">
+                                        {{ unit.device_type|capitalize }}
+                                        {% if not unit.deployed %}<span class="text-yellow-600 dark:text-yellow-400">(Benched)</span>{% endif %}
+                                    </div>
+                                </div>
+                            </div>
+                            <div class="flex items-center gap-2">
+                                {% if unit.deployed_with_modem_id %}
+                                <span class="px-2 py-1 text-xs rounded-full bg-green-100 dark:bg-green-900/30 text-green-700 dark:text-green-400">
+                                    → {{ unit.deployed_with_modem_id }}
+                                </span>
+                                {% endif %}
+                                <div class="w-5 h-5 rounded-full border-2 border-gray-300 dark:border-gray-600 flex items-center justify-center selection-indicator">
+                                    <svg class="w-3 h-3 text-seismo-orange hidden check-icon" fill="currentColor" viewBox="0 0 20 20">
+                                        <path fill-rule="evenodd" d="M16.707 5.293a1 1 0 010 1.414l-8 8a1 1 0 01-1.414 0l-4-4a1 1 0 011.414-1.414L8 12.586l7.293-7.293a1 1 0 011.414 0z" clip-rule="evenodd"></path>
+                                    </svg>
+                                </div>
+                            </div>
+                        </div>
+                    </div>
+                    {% else %}
+                    <div class="p-8 text-center text-gray-500 dark:text-gray-400">
+                        No recorders found in roster
+                    </div>
+                    {% endfor %}
+                </div>
+            </div>
+        </div>
+
+        <!-- Right Column: Modems -->
+        <div class="bg-white dark:bg-slate-800 rounded-lg shadow border border-gray-200 dark:border-gray-700">
+            <div class="px-4 py-3 border-b border-gray-200 dark:border-gray-700">
+                <div class="flex items-center justify-between mb-3">
+                    <h2 class="text-lg font-semibold text-gray-900 dark:text-white flex items-center gap-2">
+                        <svg class="w-5 h-5 text-seismo-orange" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M8.111 16.404a5.5 5.5 0 017.778 0M12 20h.01m-7.08-7.071c3.904-3.905 10.236-3.905 14.141 0M1.394 9.393c5.857-5.857 15.355-5.857 21.213 0"></path>
+                        </svg>
+                        Modems
+                        <span id="modem-count" class="text-sm font-normal text-gray-500 dark:text-gray-400">({{ modems|length }})</span>
+                    </h2>
+                </div>
+                <!-- Modem Search & Filters -->
+                <div class="space-y-2">
+                    <input type="text" id="modem-search" placeholder="Search by ID, IP, or phone..."
+                           class="w-full px-3 py-2 rounded-lg border border-gray-300 dark:border-gray-600 bg-white dark:bg-slate-700 text-gray-900 dark:text-white text-sm focus:ring-2 focus:ring-seismo-orange focus:border-seismo-orange"
+                           oninput="filterModems()">
+                    <div class="flex items-center gap-4">
+                        <label class="flex items-center gap-2 cursor-pointer">
+                            <input type="checkbox" id="modem-hide-paired" onchange="filterModems()" class="rounded border-gray-300 dark:border-gray-600 text-seismo-orange focus:ring-seismo-orange">
+                            <span class="text-xs text-gray-600 dark:text-gray-400">Hide paired</span>
+                        </label>
+                        <label class="flex items-center gap-2 cursor-pointer">
+                            <input type="checkbox" id="modem-deployed-only" onchange="filterModems()" class="rounded border-gray-300 dark:border-gray-600 text-seismo-orange focus:ring-seismo-orange">
+                            <span class="text-xs text-gray-600 dark:text-gray-400">Deployed only</span>
+                        </label>
+                    </div>
+                </div>
+            </div>
+            <div class="max-h-[600px] overflow-y-auto">
+                <div id="modems-list" class="divide-y divide-gray-200 dark:divide-gray-700">
+                    {% for unit in modems %}
+                    <div class="device-row modem-row p-3 hover:bg-gray-50 dark:hover:bg-gray-700/50 cursor-pointer transition-colors"
+                         data-id="{{ unit.id }}"
+                         data-deployed="{{ unit.deployed|lower }}"
+                         data-paired-with="{{ unit.deployed_with_unit_id or '' }}"
+                         data-ip="{{ unit.ip_address or '' }}"
+                         data-phone="{{ unit.phone_number or '' }}"
+                         onclick="selectModem('{{ unit.id }}')">
+                        <div class="flex items-center justify-between">
+                            <div class="flex items-center gap-3">
+                                <div class="w-8 h-8 rounded-full bg-amber-100 dark:bg-amber-900/30 flex items-center justify-center text-amber-600 dark:text-amber-400">
+                                    <svg class="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                                        <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M8.111 16.404a5.5 5.5 0 017.778 0M12 20h.01m-7.08-7.071c3.904-3.905 10.236-3.905 14.141 0M1.394 9.393c5.857-5.857 15.355-5.857 21.213 0"></path>
+                                    </svg>
+                                </div>
+                                <div>
+                                    <div class="font-mono font-medium text-gray-900 dark:text-white">{{ unit.id }}</div>
+                                    <div class="text-xs text-gray-500 dark:text-gray-400">
+                                        {% if unit.ip_address %}<span class="font-mono">{{ unit.ip_address }}</span>{% endif %}
+                                        {% if unit.phone_number %}{% if unit.ip_address %} · {% endif %}{{ unit.phone_number }}{% endif %}
+                                        {% if not unit.ip_address and not unit.phone_number %}Modem{% endif %}
+                                        {% if not unit.deployed %}<span class="text-yellow-600 dark:text-yellow-400">(Benched)</span>{% endif %}
+                                    </div>
+                                </div>
+                            </div>
+                            <div class="flex items-center gap-2">
+                                {% if unit.deployed_with_unit_id %}
+                                <span class="px-2 py-1 text-xs rounded-full bg-green-100 dark:bg-green-900/30 text-green-700 dark:text-green-400">
+                                    ← {{ unit.deployed_with_unit_id }}
+                                </span>
+                                {% endif %}
+                                <div class="w-5 h-5 rounded-full border-2 border-gray-300 dark:border-gray-600 flex items-center justify-center selection-indicator">
+                                    <svg class="w-3 h-3 text-seismo-orange hidden check-icon" fill="currentColor" viewBox="0 0 20 20">
+                                        <path fill-rule="evenodd" d="M16.707 5.293a1 1 0 010 1.414l-8 8a1 1 0 01-1.414 0l-4-4a1 1 0 011.414-1.414L8 12.586l7.293-7.293a1 1 0 011.414 0z" clip-rule="evenodd"></path>
+                                    </svg>
+                                </div>
+                            </div>
+                        </div>
+                    </div>
+                    {% else %}
+                    <div class="p-8 text-center text-gray-500 dark:text-gray-400">
+                        No modems found in roster
+                    </div>
+                    {% endfor %}
+                </div>
+            </div>
+        </div>
+    </div>
+
+    <!-- Existing Pairings Section -->
+    <div class="mt-8 bg-white dark:bg-slate-800 rounded-lg shadow border border-gray-200 dark:border-gray-700">
+        <div class="px-4 py-3 border-b border-gray-200 dark:border-gray-700">
+            <h2 class="text-lg font-semibold text-gray-900 dark:text-white flex items-center gap-2">
+                <svg class="w-5 h-5 text-green-500" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                    <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M13.828 10.172a4 4 0 00-5.656 0l-4 4a4 4 0 105.656 5.656l1.102-1.101m-.758-4.899a4 4 0 005.656 0l4-4a4 4 0 00-5.656-5.656l-1.1 1.1"></path>
+                </svg>
+                Existing Pairings
+                <span id="pairing-count" class="text-sm font-normal text-gray-500 dark:text-gray-400">({{ pairings|length }})</span>
+            </h2>
+        </div>
+        <div class="max-h-[400px] overflow-y-auto">
+            <div id="pairings-list" class="divide-y divide-gray-200 dark:divide-gray-700">
+                {% for pairing in pairings %}
+                <div class="pairing-row p-3 flex items-center justify-between hover:bg-gray-50 dark:hover:bg-gray-700/50">
+                    <div class="flex items-center gap-4">
+                        <div class="flex items-center gap-2">
+                            <span class="px-2 py-1 text-sm font-mono rounded bg-blue-100 dark:bg-blue-900/30 text-blue-700 dark:text-blue-400">
+                                {{ pairing.recorder_id }}
+                            </span>
+                            <span class="text-xs text-gray-500 dark:text-gray-400">{{ pairing.recorder_type }}</span>
+                        </div>
+                        <svg class="w-5 h-5 text-gray-400" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M8 7h12m0 0l-4-4m4 4l-4 4m0 6H4m0 0l4 4m-4-4l4-4"></path>
+                        </svg>
+                        <div class="flex items-center gap-2">
+                            <span class="px-2 py-1 text-sm font-mono rounded bg-amber-100 dark:bg-amber-900/30 text-amber-700 dark:text-amber-400">
+                                {{ pairing.modem_id }}
+                            </span>
+                            {% if pairing.modem_ip %}
+                            <span class="text-xs font-mono text-gray-500 dark:text-gray-400">{{ pairing.modem_ip }}</span>
+                            {% endif %}
+                        </div>
+                    </div>
+                    <button onclick="unpairDevices('{{ pairing.recorder_id }}', '{{ pairing.modem_id }}')"
+                            class="p-2 text-red-600 dark:text-red-400 hover:bg-red-100 dark:hover:bg-red-900/30 rounded-lg transition-colors"
+                            title="Unpair devices">
+                        <svg class="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M6 18L18 6M6 6l12 12"></path>
+                        </svg>
+                    </button>
+                </div>
+                {% else %}
+                <div class="p-8 text-center text-gray-500 dark:text-gray-400">
+                    No pairings found. Select a recorder and modem above to create one.
+                </div>
+                {% endfor %}
+            </div>
+        </div>
+    </div>
+</div>
+
+<!-- Toast notification -->
+<div id="toast" class="fixed bottom-4 right-4 px-4 py-3 rounded-lg shadow-lg transform translate-y-full opacity-0 transition-all duration-300 z-50"></div>
+
+<script>
+let selectedRecorder = null;
+let selectedModem = null;
+
+function selectRecorder(id) {
+    // Deselect previous
+    document.querySelectorAll('.recorder-row').forEach(row => {
+        row.classList.remove('bg-seismo-orange/10', 'dark:bg-seismo-orange/20');
+        row.querySelector('.selection-indicator').classList.remove('border-seismo-orange', 'bg-seismo-orange');
+        row.querySelector('.selection-indicator').classList.add('border-gray-300', 'dark:border-gray-600');
+        row.querySelector('.check-icon').classList.add('hidden');
+    });
+
+    // Toggle selection
+    if (selectedRecorder === id) {
+        selectedRecorder = null;
+        document.getElementById('selected-recorder').textContent = 'None selected';
+    } else {
+        selectedRecorder = id;
+        document.getElementById('selected-recorder').textContent = id;
+
+        // Highlight selected
+        const row = document.querySelector(`.recorder-row[data-id="${id}"]`);
+        if (row) {
+            row.classList.add('bg-seismo-orange/10', 'dark:bg-seismo-orange/20');
+            row.querySelector('.selection-indicator').classList.remove('border-gray-300', 'dark:border-gray-600');
+            row.querySelector('.selection-indicator').classList.add('border-seismo-orange', 'bg-seismo-orange');
+            row.querySelector('.check-icon').classList.remove('hidden');
+        }
+    }
+
+    updateButtons();
+}
+
+function selectModem(id) {
+    // Deselect previous
+    document.querySelectorAll('.modem-row').forEach(row => {
+        row.classList.remove('bg-seismo-orange/10', 'dark:bg-seismo-orange/20');
+        row.querySelector('.selection-indicator').classList.remove('border-seismo-orange', 'bg-seismo-orange');
+        row.querySelector('.selection-indicator').classList.add('border-gray-300', 'dark:border-gray-600');
+        row.querySelector('.check-icon').classList.add('hidden');
+    });
+
+    // Toggle selection
+    if (selectedModem === id) {
+        selectedModem = null;
+        document.getElementById('selected-modem').textContent = 'None selected';
+    } else {
+        selectedModem = id;
+        document.getElementById('selected-modem').textContent = id;
+
+        // Highlight selected
+        const row = document.querySelector(`.modem-row[data-id="${id}"]`);
+        if (row) {
+            row.classList.add('bg-seismo-orange/10', 'dark:bg-seismo-orange/20');
+            row.querySelector('.selection-indicator').classList.remove('border-gray-300', 'dark:border-gray-600');
+            row.querySelector('.selection-indicator').classList.add('border-seismo-orange', 'bg-seismo-orange');
+            row.querySelector('.check-icon').classList.remove('hidden');
+        }
+    }
+
+    updateButtons();
+}
+
+function updateButtons() {
+    const pairBtn = document.getElementById('pair-btn');
+    const clearBtn = document.getElementById('clear-selection-btn');
+
+    pairBtn.disabled = !(selectedRecorder && selectedModem);
+    clearBtn.disabled = !(selectedRecorder || selectedModem);
+}
+
+function clearSelection() {
+    if (selectedRecorder) selectRecorder(selectedRecorder);
+    if (selectedModem) selectModem(selectedModem);
+}
+
+function filterRecorders() {
+    const searchTerm = document.getElementById('recorder-search').value.toLowerCase().trim();
+    const hidePaired = document.getElementById('recorder-hide-paired').checked;
+    const deployedOnly = document.getElementById('recorder-deployed-only').checked;
+
+    let visibleRecorders = 0;
+
+    document.querySelectorAll('.recorder-row').forEach(row => {
+        const id = row.dataset.id.toLowerCase();
+        const pairedWith = row.dataset.pairedWith;
+        const deployed = row.dataset.deployed === 'true';
+
+        let show = true;
+        if (searchTerm && !id.includes(searchTerm)) show = false;
+        if (hidePaired && pairedWith) show = false;
+        if (deployedOnly && !deployed) show = false;
+
+        row.style.display = show ? '' : 'none';
+        if (show) visibleRecorders++;
+    });
+
+    document.getElementById('recorder-count').textContent = `(${visibleRecorders})`;
+}
+
+function filterModems() {
+    const searchTerm = document.getElementById('modem-search').value.toLowerCase().trim();
+    const hidePaired = document.getElementById('modem-hide-paired').checked;
+    const deployedOnly = document.getElementById('modem-deployed-only').checked;
+
+    let visibleModems = 0;
+
+    document.querySelectorAll('.modem-row').forEach(row => {
+        const id = row.dataset.id.toLowerCase();
+        const ip = (row.dataset.ip || '').toLowerCase();
+        const phone = (row.dataset.phone || '').toLowerCase();
+        const pairedWith = row.dataset.pairedWith;
+        const deployed = row.dataset.deployed === 'true';
+
+        let show = true;
+        if (searchTerm && !id.includes(searchTerm) && !ip.includes(searchTerm) && !phone.includes(searchTerm)) show = false;
+        if (hidePaired && pairedWith) show = false;
+        if (deployedOnly && !deployed) show = false;
+
+        row.style.display = show ? '' : 'none';
+        if (show) visibleModems++;
+    });
+
+    document.getElementById('modem-count').textContent = `(${visibleModems})`;
+}
+
+function saveScrollPositions() {
+    const recordersList = document.getElementById('recorders-list').parentElement;
+    const modemsList = document.getElementById('modems-list').parentElement;
+    const pairingsList = document.getElementById('pairings-list').parentElement;
+
+    sessionStorage.setItem('pairDevices_recorderScroll', recordersList.scrollTop);
+    sessionStorage.setItem('pairDevices_modemScroll', modemsList.scrollTop);
+    sessionStorage.setItem('pairDevices_pairingScroll', pairingsList.scrollTop);
+
+    // Save recorder filter state
+    sessionStorage.setItem('pairDevices_recorderSearch', document.getElementById('recorder-search').value);
+    sessionStorage.setItem('pairDevices_recorderHidePaired', document.getElementById('recorder-hide-paired').checked);
+    sessionStorage.setItem('pairDevices_recorderDeployedOnly', document.getElementById('recorder-deployed-only').checked);
+
+    // Save modem filter state
+    sessionStorage.setItem('pairDevices_modemSearch', document.getElementById('modem-search').value);
+    sessionStorage.setItem('pairDevices_modemHidePaired', document.getElementById('modem-hide-paired').checked);
+    sessionStorage.setItem('pairDevices_modemDeployedOnly', document.getElementById('modem-deployed-only').checked);
+}
+
+function restoreScrollPositions() {
+    const recorderScroll = sessionStorage.getItem('pairDevices_recorderScroll');
+    const modemScroll = sessionStorage.getItem('pairDevices_modemScroll');
+    const pairingScroll = sessionStorage.getItem('pairDevices_pairingScroll');
+
+    if (recorderScroll) {
+        document.getElementById('recorders-list').parentElement.scrollTop = parseInt(recorderScroll);
+    }
+    if (modemScroll) {
+        document.getElementById('modems-list').parentElement.scrollTop = parseInt(modemScroll);
+    }
+    if (pairingScroll) {
+        document.getElementById('pairings-list').parentElement.scrollTop = parseInt(pairingScroll);
+    }
+
+    // Restore recorder filter state
+    const recorderSearch = sessionStorage.getItem('pairDevices_recorderSearch');
+    const recorderHidePaired = sessionStorage.getItem('pairDevices_recorderHidePaired');
+    const recorderDeployedOnly = sessionStorage.getItem('pairDevices_recorderDeployedOnly');
+
+    if (recorderSearch) document.getElementById('recorder-search').value = recorderSearch;
+    if (recorderHidePaired === 'true') document.getElementById('recorder-hide-paired').checked = true;
+    if (recorderDeployedOnly === 'true') document.getElementById('recorder-deployed-only').checked = true;
+
+    // Restore modem filter state
+    const modemSearch = sessionStorage.getItem('pairDevices_modemSearch');
+    const modemHidePaired = sessionStorage.getItem('pairDevices_modemHidePaired');
+    const modemDeployedOnly = sessionStorage.getItem('pairDevices_modemDeployedOnly');
+
+    if (modemSearch) document.getElementById('modem-search').value = modemSearch;
+    if (modemHidePaired === 'true') document.getElementById('modem-hide-paired').checked = true;
+    if (modemDeployedOnly === 'true') document.getElementById('modem-deployed-only').checked = true;
+
+    // Apply filters if any were set
+    if (recorderSearch || recorderHidePaired === 'true' || recorderDeployedOnly === 'true') {
+        filterRecorders();
+    }
+    if (modemSearch || modemHidePaired === 'true' || modemDeployedOnly === 'true') {
+        filterModems();
+    }
+
+    // Clear stored values
+    sessionStorage.removeItem('pairDevices_recorderScroll');
+    sessionStorage.removeItem('pairDevices_modemScroll');
+    sessionStorage.removeItem('pairDevices_pairingScroll');
+    sessionStorage.removeItem('pairDevices_recorderSearch');
+    sessionStorage.removeItem('pairDevices_recorderHidePaired');
+    sessionStorage.removeItem('pairDevices_recorderDeployedOnly');
+    sessionStorage.removeItem('pairDevices_modemSearch');
+    sessionStorage.removeItem('pairDevices_modemHidePaired');
+    sessionStorage.removeItem('pairDevices_modemDeployedOnly');
+}
+
+// Restore scroll positions on page load
+document.addEventListener('DOMContentLoaded', restoreScrollPositions);
+
+async function pairDevices() {
+    if (!selectedRecorder || !selectedModem) return;
+
+    const pairBtn = document.getElementById('pair-btn');
+    pairBtn.disabled = true;
+    pairBtn.textContent = 'Pairing...';
+
+    try {
+        const response = await fetch('/api/roster/pair-devices', {
+            method: 'POST',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({
+                recorder_id: selectedRecorder,
+                modem_id: selectedModem
+            })
+        });
+
+        const result = await response.json();
+
+        if (response.ok) {
+            showToast(`Paired ${selectedRecorder} with ${selectedModem}`, 'success');
+            // Save scroll positions before reload
+            saveScrollPositions();
+            setTimeout(() => window.location.reload(), 500);
+        } else {
+            showToast(result.detail || 'Failed to pair devices', 'error');
+        }
+    } catch (error) {
+        showToast('Error pairing devices: ' + error.message, 'error');
+    } finally {
+        pairBtn.disabled = false;
+        pairBtn.textContent = 'Pair Devices';
+    }
+}
+
+async function unpairDevices(recorderId, modemId) {
+    if (!confirm(`Unpair ${recorderId} from ${modemId}?`)) return;
+
+    try {
+        const response = await fetch('/api/roster/unpair-devices', {
+            method: 'POST',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({
+                recorder_id: recorderId,
+                modem_id: modemId
+            })
+        });
+
+        const result = await response.json();
+
+        if (response.ok) {
+            showToast(`Unpaired ${recorderId} from ${modemId}`, 'success');
+            // Save scroll positions before reload
+            saveScrollPositions();
+            setTimeout(() => window.location.reload(), 500);
+        } else {
+            showToast(result.detail || 'Failed to unpair devices', 'error');
+        }
+    } catch (error) {
+        showToast('Error unpairing devices: ' + error.message, 'error');
+    }
+}
+
+function showToast(message, type = 'info') {
+    const toast = document.getElementById('toast');
+    toast.textContent = message;
+    toast.className = 'fixed bottom-4 right-4 px-4 py-3 rounded-lg shadow-lg transform transition-all duration-300 z-50';
+
+    if (type === 'success') {
+        toast.classList.add('bg-green-500', 'text-white');
+    } else if (type === 'error') {
+        toast.classList.add('bg-red-500', 'text-white');
+    } else {
+        toast.classList.add('bg-gray-800', 'text-white');
+    }
+
+    // Show
+    toast.classList.remove('translate-y-full', 'opacity-0');
+
+    // Hide after 3 seconds
+    setTimeout(() => {
+        toast.classList.add('translate-y-full', 'opacity-0');
+    }, 3000);
+}
+</script>
+
+<style>
+.bg-seismo-orange\/10 {
+    background-color: rgb(249 115 22 / 0.1);
+}
+.dark\:bg-seismo-orange\/20:is(.dark *) {
+    background-color: rgb(249 115 22 / 0.2);
+}
+</style>
+{% endblock %}

templates/partials/devices_table.html

@@ -104,8 +104,13 @@
                             {% if unit.phone_number %}
                                 <div>{{ unit.phone_number }}</div>
                             {% endif %}
-                            {% if unit.hardware_model %}
+                            {% if unit.deployed_with_unit_id %}
-                                <div class="text-gray-500 dark:text-gray-500">{{ unit.hardware_model }}</div>
+                                <div>
+                                    <span class="text-gray-500 dark:text-gray-500">Linked:</span>
+                                    <a href="/unit/{{ unit.deployed_with_unit_id }}" class="text-seismo-orange hover:underline font-medium">
+                                        {{ unit.deployed_with_unit_id }}
+                                    </a>
+                                </div>
                             {% endif %}
                         {% else %}
                             {% if unit.next_calibration_due %}
@@ -126,7 +131,7 @@
                     </div>
                 </td>
                 <td class="px-6 py-4 whitespace-nowrap">
-                    <div class="text-sm text-gray-500 dark:text-gray-400">{{ unit.last_seen }}</div>
+                    <div class="text-sm text-gray-500 dark:text-gray-400 last-seen-cell" data-iso="{{ unit.last_seen }}">{{ unit.last_seen }}</div>
                 </td>
                 <td class="px-6 py-4 whitespace-nowrap">
                     <div class="text-sm
@@ -345,6 +350,39 @@
 </style>
 
 <script>
+(function() {
+    // User's configured timezone from settings (defaults to America/New_York)
+    const userTimezone = '{{ user_timezone | default("America/New_York") }}';
+
+    // Format ISO timestamp to human-readable format in user's timezone
+    function formatLastSeenLocal(isoString) {
+        if (!isoString || isoString === 'Never' || isoString === 'N/A') {
+            return isoString || 'Never';
+        }
+        try {
+            const date = new Date(isoString);
+            if (isNaN(date.getTime())) return isoString;
+
+            // Format in user's configured timezone
+            return date.toLocaleString('en-US', {
+                timeZone: userTimezone,
+                month: 'short',
+                day: 'numeric',
+                hour: 'numeric',
+                minute: '2-digit',
+                hour12: true
+            });
+        } catch (e) {
+            return isoString;
+        }
+    }
+
+    // Format all last-seen cells on page load
+    document.querySelectorAll('.last-seen-cell').forEach(cell => {
+        const isoDate = cell.getAttribute('data-iso');
+        cell.textContent = formatLastSeenLocal(isoDate);
+    });
+
     // Update timestamp
     const timestampElement = document.getElementById('last-updated');
     if (timestampElement) {
@@ -365,20 +403,23 @@
         };
         return acc;
     }, {});
+})();
 
-    // Sorting state
+    // Sorting state (needs to persist across swaps)
-    let currentSort = { column: null, direction: 'asc' };
+    if (typeof window.currentSort === 'undefined') {
+        window.currentSort = { column: null, direction: 'asc' };
+    }
 
     function sortTable(column) {
         const tbody = document.getElementById('roster-tbody');
         const rows = Array.from(tbody.getElementsByTagName('tr'));
 
         // Determine sort direction
-        if (currentSort.column === column) {
+        if (window.currentSort.column === column) {
-            currentSort.direction = currentSort.direction === 'asc' ? 'desc' : 'asc';
+            window.currentSort.direction = window.currentSort.direction === 'asc' ? 'desc' : 'asc';
         } else {
-            currentSort.column = column;
+            window.currentSort.column = column;
-            currentSort.direction = 'asc';
+            window.currentSort.direction = 'asc';
         }
 
         // Sort rows
@@ -406,8 +447,8 @@
                 bVal = bVal.toLowerCase();
             }
 
-            if (aVal < bVal) return currentSort.direction === 'asc' ? -1 : 1;
+            if (aVal < bVal) return window.currentSort.direction === 'asc' ? -1 : 1;
-            if (aVal > bVal) return currentSort.direction === 'asc' ? 1 : -1;
+            if (aVal > bVal) return window.currentSort.direction === 'asc' ? 1 : -1;
             return 0;
         });
 
@@ -443,10 +484,10 @@
         });
 
         // Set current indicator
-        if (currentSort.column) {
+        if (window.currentSort.column) {
-            const indicator = document.querySelector(`.sort-indicator[data-column="${currentSort.column}"]`);
+            const indicator = document.querySelector(`.sort-indicator[data-column="${window.currentSort.column}"]`);
             if (indicator) {
-                indicator.className = `sort-indicator ${currentSort.direction}`;
+                indicator.className = `sort-indicator ${window.currentSort.direction}`;
             }
         }
     }

templates/partials/modem_list.html

@@ -1,89 +1,127 @@
 <!-- Modem List -->
 {% if modems %}
-<div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
+<div class="overflow-x-auto">
+    <table class="w-full">
+        <thead class="bg-gray-50 dark:bg-slate-700 border-b border-gray-200 dark:border-gray-600">
+            <tr>
+                <th class="px-4 py-3 text-left text-xs font-medium text-gray-700 dark:text-gray-300 uppercase tracking-wider">Unit ID</th>
+                <th class="px-4 py-3 text-left text-xs font-medium text-gray-700 dark:text-gray-300 uppercase tracking-wider">Status</th>
+                <th class="px-4 py-3 text-left text-xs font-medium text-gray-700 dark:text-gray-300 uppercase tracking-wider">IP Address</th>
+                <th class="px-4 py-3 text-left text-xs font-medium text-gray-700 dark:text-gray-300 uppercase tracking-wider">Phone</th>
+                <th class="px-4 py-3 text-left text-xs font-medium text-gray-700 dark:text-gray-300 uppercase tracking-wider">Paired Device</th>
+                <th class="px-4 py-3 text-left text-xs font-medium text-gray-700 dark:text-gray-300 uppercase tracking-wider">Location</th>
+                <th class="px-4 py-3 text-right text-xs font-medium text-gray-700 dark:text-gray-300 uppercase tracking-wider">Actions</th>
+            </tr>
+        </thead>
+        <tbody class="divide-y divide-gray-200 dark:divide-gray-700">
             {% for modem in modems %}
-    <div class="bg-gray-50 dark:bg-gray-800 rounded-lg p-4 border border-transparent hover:border-seismo-orange transition-colors">
+            <tr class="hover:bg-gray-50 dark:hover:bg-slate-700 transition-colors">
-        <div class="flex items-start justify-between gap-4">
+                <td class="px-4 py-3 whitespace-nowrap">
-            <div class="min-w-0 flex-1">
                     <div class="flex items-center gap-2">
-                    <a href="/unit/{{ modem.id }}" class="font-semibold text-gray-900 dark:text-white hover:text-seismo-orange">
+                        <a href="/unit/{{ modem.id }}" class="font-medium text-blue-600 dark:text-blue-400 hover:underline">
                             {{ modem.id }}
                         </a>
                         {% if modem.hardware_model %}
-                        <span class="text-xs text-gray-500 dark:text-gray-400">{{ modem.hardware_model }}</span>
+                        <span class="text-xs text-gray-500 dark:text-gray-400">({{ modem.hardware_model }})</span>
                         {% endif %}
                     </div>
-
+                </td>
-                {% if modem.ip_address %}
+                <td class="px-4 py-3 whitespace-nowrap">
-                    <p class="text-sm text-gray-600 dark:text-gray-400 font-mono mt-1">{{ modem.ip_address }}</p>
-                {% else %}
-                    <p class="text-sm text-red-500 mt-1">No IP configured</p>
-                {% endif %}
-
-                {% if modem.phone_number %}
-                    <p class="text-xs text-gray-500 dark:text-gray-400 mt-1">{{ modem.phone_number }}</p>
-                {% endif %}
-            </div>
-
-            <!-- Status Badge -->
                     {% if modem.status == "retired" %}
-                <span class="shrink-0 px-2 py-1 text-xs font-medium bg-gray-200 text-gray-700 dark:bg-gray-700 dark:text-gray-300 rounded-full">Retired</span>
+                    <span class="inline-flex items-center px-2.5 py-0.5 rounded-full text-xs font-medium bg-gray-200 text-gray-700 dark:bg-gray-700 dark:text-gray-300">
+                        Retired
+                    </span>
                     {% elif modem.status == "benched" %}
-                <span class="shrink-0 px-2 py-1 text-xs font-medium bg-amber-100 text-amber-800 dark:bg-amber-900/30 dark:text-amber-300 rounded-full">Benched</span>
+                    <span class="inline-flex items-center px-2.5 py-0.5 rounded-full text-xs font-medium bg-amber-100 text-amber-800 dark:bg-amber-900/30 dark:text-amber-300">
+                        Benched
+                    </span>
                     {% elif modem.status == "in_use" %}
-                <span class="shrink-0 px-2 py-1 text-xs font-medium bg-green-100 text-green-800 dark:bg-green-900/30 dark:text-green-300 rounded-full">In Use</span>
+                    <span class="inline-flex items-center px-2.5 py-0.5 rounded-full text-xs font-medium bg-green-100 text-green-800 dark:bg-green-900/30 dark:text-green-300">
+                        In Use
+                    </span>
                     {% elif modem.status == "spare" %}
-                <span class="shrink-0 px-2 py-1 text-xs font-medium bg-blue-100 text-blue-800 dark:bg-blue-900/30 dark:text-blue-300 rounded-full">Spare</span>
+                    <span class="inline-flex items-center px-2.5 py-0.5 rounded-full text-xs font-medium bg-blue-100 text-blue-800 dark:bg-blue-900/30 dark:text-blue-300">
+                        Spare
+                    </span>
+                    {% else %}
+                    <span class="inline-flex items-center px-2.5 py-0.5 rounded-full text-xs font-medium bg-gray-100 text-gray-800 dark:bg-gray-700 dark:text-gray-300">
+                        —
+                    </span>
                     {% endif %}
-        </div>
+                </td>
-
+                <td class="px-4 py-3 whitespace-nowrap text-sm">
-        <!-- Paired Device -->
+                    {% if modem.ip_address %}
+                    <span class="font-mono text-gray-900 dark:text-gray-300">{{ modem.ip_address }}</span>
+                    {% else %}
+                    <span class="text-gray-400 dark:text-gray-600">—</span>
+                    {% endif %}
+                </td>
+                <td class="px-4 py-3 whitespace-nowrap text-sm text-gray-900 dark:text-gray-300">
+                    {% if modem.phone_number %}
+                    {{ modem.phone_number }}
+                    {% else %}
+                    <span class="text-gray-400 dark:text-gray-600">—</span>
+                    {% endif %}
+                </td>
+                <td class="px-4 py-3 whitespace-nowrap text-sm">
                     {% if modem.paired_device %}
-        <div class="mt-3 pt-3 border-t border-gray-200 dark:border-gray-700">
+                    <a href="/unit/{{ modem.paired_device.id }}" class="text-blue-600 dark:text-blue-400 hover:underline">
-            <p class="text-xs text-gray-500 dark:text-gray-400">Paired with:</p>
-            <a href="/unit/{{ modem.paired_device.id }}" class="text-sm text-seismo-orange hover:underline">
                         {{ modem.paired_device.id }}
-                <span class="text-gray-500">({{ modem.paired_device.device_type }})</span>
+                        <span class="text-gray-500 dark:text-gray-400">({{ modem.paired_device.device_type }})</span>
                     </a>
-        </div>
+                    {% else %}
+                    <span class="text-gray-400 dark:text-gray-600">None</span>
                     {% endif %}
-
+                </td>
-        <!-- Location if available -->
+                <td class="px-4 py-3 text-sm text-gray-900 dark:text-gray-300">
-        {% if modem.location or modem.project_id %}
-        <div class="mt-2 text-xs text-gray-500 dark:text-gray-400">
                     {% if modem.project_id %}
-                <span class="bg-gray-200 dark:bg-gray-700 px-1.5 py-0.5 rounded">{{ modem.project_id }}</span>
+                    <span class="bg-gray-200 dark:bg-gray-700 px-1.5 py-0.5 rounded text-xs mr-1">{{ modem.project_id }}</span>
                     {% endif %}
                     {% if modem.location %}
-                {{ modem.location }}
+                    <span class="truncate max-w-xs inline-block" title="{{ modem.location }}">{{ modem.location }}</span>
+                    {% elif not modem.project_id %}
+                    <span class="text-gray-400 dark:text-gray-600">—</span>
                     {% endif %}
-        </div>
+                </td>
-        {% endif %}
+                <td class="px-4 py-3 whitespace-nowrap text-right text-sm">
-
+                    <div class="flex items-center justify-end gap-2">
-        <!-- Quick Actions -->
-        <div class="mt-3 flex gap-2">
                         <button onclick="pingModem('{{ modem.id }}')"
                                 id="ping-btn-{{ modem.id }}"
-                    class="text-xs px-3 py-1.5 bg-blue-100 hover:bg-blue-200 text-blue-700 dark:bg-blue-900/30 dark:hover:bg-blue-900/50 dark:text-blue-300 rounded transition-colors">
+                                class="text-xs px-2 py-1 bg-blue-100 hover:bg-blue-200 text-blue-700 dark:bg-blue-900/30 dark:hover:bg-blue-900/50 dark:text-blue-300 rounded transition-colors">
                             Ping
                         </button>
-            <a href="/unit/{{ modem.id }}"
+                        <a href="/unit/{{ modem.id }}" class="text-blue-600 dark:text-blue-400 hover:underline">
-               class="text-xs px-3 py-1.5 bg-gray-100 hover:bg-gray-200 text-gray-700 dark:bg-gray-700 dark:hover:bg-gray-600 dark:text-gray-300 rounded transition-colors">
+                            View →
-                Details
                         </a>
                     </div>
-
                     <!-- Ping Result (hidden by default) -->
-        <div id="ping-result-{{ modem.id }}" class="mt-2 text-xs hidden"></div>
+                    <div id="ping-result-{{ modem.id }}" class="mt-1 text-xs hidden"></div>
-    </div>
+                </td>
+            </tr>
             {% endfor %}
+        </tbody>
+    </table>
 </div>
+
+{% if search %}
+<div class="mt-4 text-sm text-gray-600 dark:text-gray-400">
+    Found {{ modems|length }} modem(s) matching "{{ search }}"
+</div>
+{% endif %}
+
 {% else %}
 <div class="text-center py-12 text-gray-500 dark:text-gray-400">
     <svg class="w-12 h-12 mx-auto mb-3 opacity-50" fill="none" stroke="currentColor" viewBox="0 0 24 24">
         <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M8.111 16.404a5.5 5.5 0 017.778 0M12 20h.01m-7.08-7.071c3.904-3.905 10.236-3.905 14.141 0M1.394 9.393c5.857-5.857 15.355-5.857 21.213 0"></path>
     </svg>
     <p>No modems found</p>
+    {% if search %}
+    <button onclick="document.getElementById('modem-search').value = ''; htmx.trigger('#modem-search', 'keyup');"
+            class="mt-3 text-blue-600 dark:text-blue-400 hover:underline">
+        Clear search
+    </button>
+    {% else %}
     <p class="text-sm mt-1">Add modems from the <a href="/roster" class="text-seismo-orange hover:underline">Fleet Roster</a></p>
+    {% endif %}
 </div>
 {% endif %}

templates/partials/roster_table.html

@@ -337,6 +337,7 @@
 </style>
 
 <script>
+(function() {
     // Update timestamp
     const timestampElement = document.getElementById('last-updated');
     if (timestampElement) {
@@ -357,20 +358,23 @@
         };
         return acc;
     }, {});
+})();
 
-    // Sorting state
+    // Sorting state (needs to persist across swaps)
-    let currentSort = { column: null, direction: 'asc' };
+    if (typeof window.currentSort === 'undefined') {
+        window.currentSort = { column: null, direction: 'asc' };
+    }
 
     function sortTable(column) {
         const tbody = document.getElementById('roster-tbody');
         const rows = Array.from(tbody.getElementsByTagName('tr'));
 
         // Determine sort direction
-        if (currentSort.column === column) {
+        if (window.currentSort.column === column) {
-            currentSort.direction = currentSort.direction === 'asc' ? 'desc' : 'asc';
+            window.currentSort.direction = window.currentSort.direction === 'asc' ? 'desc' : 'asc';
         } else {
-            currentSort.column = column;
+            window.currentSort.column = column;
-            currentSort.direction = 'asc';
+            window.currentSort.direction = 'asc';
         }
 
         // Sort rows
@@ -398,8 +402,8 @@
                 bVal = bVal.toLowerCase();
             }
 
-            if (aVal < bVal) return currentSort.direction === 'asc' ? -1 : 1;
+            if (aVal < bVal) return window.currentSort.direction === 'asc' ? -1 : 1;
-            if (aVal > bVal) return currentSort.direction === 'asc' ? 1 : -1;
+            if (aVal > bVal) return window.currentSort.direction === 'asc' ? 1 : -1;
             return 0;
         });
 
@@ -435,10 +439,10 @@
         });
 
         // Set current indicator
-        if (currentSort.column) {
+        if (window.currentSort.column) {
-            const indicator = document.querySelector(`.sort-indicator[data-column="${currentSort.column}"]`);
+            const indicator = document.querySelector(`.sort-indicator[data-column="${window.currentSort.column}"]`);
             if (indicator) {
-                indicator.className = `sort-indicator ${currentSort.direction}`;
+                indicator.className = `sort-indicator ${window.currentSort.direction}`;
             }
         }
     }

templates/roster.html

@@ -1154,11 +1154,20 @@
         });
     }
 
+    // Check if any modal is currently open
+    function isAnyModalOpen() {
+        const modalIds = ['addUnitModal', 'editUnitModal', 'renameUnitModal', 'importModal', 'quickCreateProjectModal'];
+        return modalIds.some(id => {
+            const modal = document.getElementById(id);
+            return modal && !modal.classList.contains('hidden');
+        });
+    }
+
     document.addEventListener('DOMContentLoaded', function() {
         // Auto-refresh device list every 30 seconds (increased from 10s to reduce flicker)
         setInterval(() => {
             const deviceContent = document.getElementById('device-content');
-            if (deviceContent && !document.querySelector('.modal:not(.hidden)')) {
+            if (deviceContent && !isAnyModalOpen()) {
                 // Only auto-refresh if no modal is open
                 refreshDeviceList();
             }

templates/unit_detail.html

@@ -43,7 +43,7 @@
             </button>
         </div>
         <div class="flex gap-3">
-            <button id="editButton" onclick="window.location.href='/roster?edit=' + unitId" class="px-4 py-2 bg-seismo-orange hover:bg-orange-600 text-white rounded-lg transition-colors flex items-center gap-2">
+            <button id="editButton" onclick="enterEditMode()" class="px-4 py-2 bg-seismo-orange hover:bg-orange-600 text-white rounded-lg transition-colors flex items-center gap-2">
                 <svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                     <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M11 5H6a2 2 0 00-2 2v11a2 2 0 002 2h11a2 2 0 002-2v-5m-1.414-9.414a2 2 0 112.828 2.828L11.828 15H9v-2.828l8.586-8.586z"></path>
                 </svg>
@@ -153,7 +153,12 @@
                     </div>
                     <div>
                         <label class="text-sm font-medium text-gray-500 dark:text-gray-400">Deployed With Modem</label>
-                        <p id="viewDeployedWithModemId" class="mt-1 text-gray-900 dark:text-white font-medium">--</p>
+                        <p id="viewDeployedWithModemContainer" class="mt-1">
+                            <a id="viewDeployedWithModemLink" href="#" class="text-seismo-orange hover:text-orange-600 font-medium hover:underline hidden">
+                                <span id="viewDeployedWithModemText">--</span>
+                            </a>
+                            <span id="viewDeployedWithModemNoLink" class="text-gray-900 dark:text-white font-medium">--</span>
+                        </p>
                     </div>
                 </div>
             </div>
@@ -336,8 +341,20 @@
                     </div>
                     <div>
                         <label class="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">Deployed With Modem</label>
-                        <input type="text" name="deployed_with_modem_id" id="deployedWithModemId" placeholder="Modem ID"
+                        <div class="flex gap-2">
-                            class="w-full px-4 py-2 rounded-lg border border-gray-300 dark:border-gray-600 bg-white dark:bg-slate-700 text-gray-900 dark:text-white focus:ring-2 focus:ring-seismo-orange">
+                            <div class="flex-1">
+                                {% set picker_id = "-detail-seismo" %}
+                                {% set input_name = "deployed_with_modem_id" %}
+                                {% include "partials/modem_picker.html" with context %}
+                            </div>
+                            <button type="button" onclick="openPairDeviceModal('seismograph')"
+                                class="px-3 py-2 bg-gray-100 dark:bg-gray-700 hover:bg-gray-200 dark:hover:bg-gray-600 text-gray-700 dark:text-gray-300 rounded-lg transition-colors flex items-center gap-1"
+                                title="Pair with modem">
+                                <svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                                    <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M13.828 10.172a4 4 0 00-5.656 0l-4 4a4 4 0 105.656 5.656l1.102-1.101m-.758-4.899a4 4 0 005.656 0l4-4a4 4 0 00-5.656-5.656l-1.1 1.1"></path>
+                                </svg>
+                            </button>
+                        </div>
                     </div>
                 </div>
             </div>
@@ -411,11 +428,20 @@
                     </div>
                     <div class="md:col-span-2">
                         <label class="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">Deployed With Modem</label>
-                        <select name="deployed_with_modem_id" id="slmDeployedWithModemId"
+                        <div class="flex gap-2">
-                            class="w-full px-4 py-2 rounded-lg border border-gray-300 dark:border-gray-600 bg-white dark:bg-slate-700 text-gray-900 dark:text-white focus:ring-2 focus:ring-seismo-orange">
+                            <div class="flex-1">
-                            <option value="">No modem assigned</option>
+                                {% set picker_id = "-detail-slm" %}
-                            <!-- Options will be populated by JavaScript -->
+                                {% set input_name = "deployed_with_modem_id" %}
-                        </select>
+                                {% include "partials/modem_picker.html" with context %}
+                            </div>
+                            <button type="button" onclick="openPairDeviceModal('sound_level_meter')"
+                                class="px-3 py-2 bg-gray-100 dark:bg-gray-700 hover:bg-gray-200 dark:hover:bg-gray-600 text-gray-700 dark:text-gray-300 rounded-lg transition-colors flex items-center gap-1"
+                                title="Pair with modem">
+                                <svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                                    <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M13.828 10.172a4 4 0 00-5.656 0l-4 4a4 4 0 105.656 5.656l1.102-1.101m-.758-4.899a4 4 0 005.656 0l4-4a4 4 0 00-5.656-5.656l-1.1 1.1"></path>
+                                </svg>
+                            </button>
+                        </div>
                         <p class="text-xs text-gray-500 dark:text-gray-400 mt-1">Select the modem that provides network connectivity for this SLM</p>
                     </div>
                 </div>
@@ -442,6 +468,54 @@
                     class="w-full px-4 py-2 rounded-lg border border-gray-300 dark:border-gray-600 bg-white dark:bg-slate-700 text-gray-900 dark:text-white focus:ring-2 focus:ring-seismo-orange"></textarea>
             </div>
 
+            <!-- Cascade to Paired Device Section -->
+            <div id="detailCascadeSection" class="hidden border-t border-gray-200 dark:border-gray-700 pt-4">
+                <div class="flex items-center gap-2 mb-3">
+                    <svg class="w-5 h-5 text-seismo-orange" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                        <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M13.828 10.172a4 4 0 00-5.656 0l-4 4a4 4 0 105.656 5.656l1.102-1.101m-.758-4.899a4 4 0 005.656 0l4-4a4 4 0 00-5.656-5.656l-1.1 1.1"></path>
+                    </svg>
+                    <span class="text-sm font-semibold text-gray-700 dark:text-gray-300">
+                        Also update paired device: <span id="detailPairedDeviceName" class="text-seismo-orange"></span>
+                    </span>
+                </div>
+                <input type="hidden" name="cascade_to_unit_id" id="detailCascadeToUnitId" value="">
+                <div class="grid grid-cols-2 md:grid-cols-3 gap-2 bg-gray-50 dark:bg-slate-700/50 rounded-lg p-3">
+                    <label class="flex items-center gap-2 cursor-pointer">
+                        <input type="checkbox" name="cascade_deployed" id="detailCascadeDeployed" value="true"
+                            class="w-4 h-4 text-seismo-orange focus:ring-seismo-orange rounded">
+                        <span class="text-sm text-gray-700 dark:text-gray-300">Deployed status</span>
+                    </label>
+                    <label class="flex items-center gap-2 cursor-pointer">
+                        <input type="checkbox" name="cascade_retired" id="detailCascadeRetired" value="true"
+                            class="w-4 h-4 text-seismo-orange focus:ring-seismo-orange rounded">
+                        <span class="text-sm text-gray-700 dark:text-gray-300">Retired status</span>
+                    </label>
+                    <label class="flex items-center gap-2 cursor-pointer">
+                        <input type="checkbox" name="cascade_project" id="detailCascadeProject" value="true"
+                            class="w-4 h-4 text-seismo-orange focus:ring-seismo-orange rounded">
+                        <span class="text-sm text-gray-700 dark:text-gray-300">Project</span>
+                    </label>
+                    <label class="flex items-center gap-2 cursor-pointer">
+                        <input type="checkbox" name="cascade_location" id="detailCascadeLocation" value="true"
+                            class="w-4 h-4 text-seismo-orange focus:ring-seismo-orange rounded">
+                        <span class="text-sm text-gray-700 dark:text-gray-300">Address</span>
+                    </label>
+                    <label class="flex items-center gap-2 cursor-pointer">
+                        <input type="checkbox" name="cascade_coordinates" id="detailCascadeCoordinates" value="true"
+                            class="w-4 h-4 text-seismo-orange focus:ring-seismo-orange rounded">
+                        <span class="text-sm text-gray-700 dark:text-gray-300">Coordinates</span>
+                    </label>
+                    <label class="flex items-center gap-2 cursor-pointer">
+                        <input type="checkbox" name="cascade_note" id="detailCascadeNote" value="true"
+                            class="w-4 h-4 text-seismo-orange focus:ring-seismo-orange rounded">
+                        <span class="text-sm text-gray-700 dark:text-gray-300">Notes</span>
+                    </label>
+                </div>
+                <p class="text-xs text-gray-500 dark:text-gray-400 mt-2">
+                    Check the fields you want to sync to the paired device
+                </p>
+            </div>
+
             <!-- Save/Cancel Buttons -->
             <div class="flex gap-3">
                 <button type="submit" class="flex-1 px-6 py-3 bg-seismo-orange hover:bg-orange-600 text-white rounded-lg font-medium transition-colors">
@@ -482,6 +556,44 @@ async function fetchProjectDisplay(projectId) {
     return projectId;
 }
 
+// Fetch modem display name (combines id, ip_address, hardware_model)
+// Also returns the actual modem ID if found (for updating picker value)
+async function fetchModemDisplay(modemIdOrIp) {
+    if (!modemIdOrIp) return { display: '', modemId: '' };
+    try {
+        // First try direct lookup by ID
+        let response = await fetch(`/api/roster/${encodeURIComponent(modemIdOrIp)}`);
+        if (response.ok) {
+            const modem = await response.json();
+            const parts = [modem.id];
+            if (modem.ip_address) parts.push(`(${modem.ip_address})`);
+            if (modem.hardware_model) parts.push(`- ${modem.hardware_model}`);
+            return { display: parts.join(' ') || modemIdOrIp, modemId: modem.id };
+        }
+
+        // If not found, maybe it's an IP address - search for it
+        response = await fetch(`/api/roster/search/modems?q=${encodeURIComponent(modemIdOrIp)}`);
+        if (response.ok) {
+            // The search returns HTML, so we need to look up differently
+            // Try fetching all modems and find by IP
+            const modemsResponse = await fetch('/api/roster/modems');
+            if (modemsResponse.ok) {
+                const modems = await modemsResponse.json();
+                const modem = modems.find(m => m.ip_address === modemIdOrIp);
+                if (modem) {
+                    const parts = [modem.id];
+                    if (modem.ip_address) parts.push(`(${modem.ip_address})`);
+                    if (modem.hardware_model) parts.push(`- ${modem.hardware_model}`);
+                    return { display: parts.join(' ') || modemIdOrIp, modemId: modem.id };
+                }
+            }
+        }
+    } catch (e) {
+        console.error('Failed to fetch modem:', e);
+    }
+    return { display: modemIdOrIp, modemId: modemIdOrIp };
+}
+
 // Load unit data on page load
 async function loadUnitData() {
     try {
@@ -634,7 +746,29 @@ function populateViewMode() {
     // Seismograph fields
     document.getElementById('viewLastCalibrated').textContent = currentUnit.last_calibrated || '--';
     document.getElementById('viewNextCalibrationDue').textContent = currentUnit.next_calibration_due || '--';
-    document.getElementById('viewDeployedWithModemId').textContent = currentUnit.deployed_with_modem_id || '--';
+
+    // Deployed with modem - show as clickable link
+    const modemLink = document.getElementById('viewDeployedWithModemLink');
+    const modemNoLink = document.getElementById('viewDeployedWithModemNoLink');
+    const modemText = document.getElementById('viewDeployedWithModemText');
+
+    if (currentUnit.deployed_with_modem_id) {
+        // Fetch modem info to get the actual ID (in case stored as IP) and display text
+        fetchModemDisplay(currentUnit.deployed_with_modem_id).then(result => {
+            if (modemText) modemText.textContent = result.display;
+            if (modemLink) {
+                modemLink.href = `/unit/${encodeURIComponent(result.modemId)}`;
+                modemLink.classList.remove('hidden');
+            }
+            if (modemNoLink) modemNoLink.classList.add('hidden');
+        });
+    } else {
+        if (modemNoLink) {
+            modemNoLink.textContent = '--';
+            modemNoLink.classList.remove('hidden');
+        }
+        if (modemLink) modemLink.classList.add('hidden');
+    }
 
     // Modem fields
     document.getElementById('viewIpAddress').textContent = currentUnit.ip_address || '--';
@@ -689,7 +823,24 @@ function populateEditForm() {
     // Seismograph fields
     document.getElementById('lastCalibrated').value = currentUnit.last_calibrated || '';
     document.getElementById('nextCalibrationDue').value = currentUnit.next_calibration_due || '';
-    document.getElementById('deployedWithModemId').value = currentUnit.deployed_with_modem_id || '';
+
+    // Populate modem picker for seismograph (uses -detail-seismo suffix)
+    const modemPickerValue = document.getElementById('modem-picker-value-detail-seismo');
+    const modemPickerSearch = document.getElementById('modem-picker-search-detail-seismo');
+    const modemPickerClear = document.getElementById('modem-picker-clear-detail-seismo');
+    if (currentUnit.deployed_with_modem_id) {
+        // Fetch modem display info (handles both modem ID and IP address lookups)
+        fetchModemDisplay(currentUnit.deployed_with_modem_id).then(result => {
+            // Update the hidden value with the actual modem ID (in case it was stored as IP)
+            if (modemPickerValue) modemPickerValue.value = result.modemId || currentUnit.deployed_with_modem_id;
+            if (modemPickerSearch) modemPickerSearch.value = result.display;
+            if (modemPickerClear) modemPickerClear.classList.remove('hidden');
+        });
+    } else {
+        if (modemPickerValue) modemPickerValue.value = '';
+        if (modemPickerSearch) modemPickerSearch.value = '';
+        if (modemPickerClear) modemPickerClear.classList.add('hidden');
+    }
 
     // Modem fields
     document.getElementById('ipAddress').value = currentUnit.ip_address || '';
@@ -703,10 +854,69 @@ function populateEditForm() {
     document.getElementById('slmFrequencyWeighting').value = currentUnit.slm_frequency_weighting || '';
     document.getElementById('slmTimeWeighting').value = currentUnit.slm_time_weighting || '';
     document.getElementById('slmMeasurementRange').value = currentUnit.slm_measurement_range || '';
-    document.getElementById('slmDeployedWithModemId').value = currentUnit.deployed_with_modem_id || '';
+
+    // Populate modem picker for SLM (uses -detail-slm suffix)
+    const slmModemPickerValue = document.getElementById('modem-picker-value-detail-slm');
+    const slmModemPickerSearch = document.getElementById('modem-picker-search-detail-slm');
+    const slmModemPickerClear = document.getElementById('modem-picker-clear-detail-slm');
+    if (currentUnit.deployed_with_modem_id) {
+        // Fetch modem display info (handles both modem ID and IP address lookups)
+        fetchModemDisplay(currentUnit.deployed_with_modem_id).then(result => {
+            // Update the hidden value with the actual modem ID (in case it was stored as IP)
+            if (slmModemPickerValue) slmModemPickerValue.value = result.modemId || currentUnit.deployed_with_modem_id;
+            if (slmModemPickerSearch) slmModemPickerSearch.value = result.display;
+            if (slmModemPickerClear) slmModemPickerClear.classList.remove('hidden');
+        });
+    } else {
+        if (slmModemPickerValue) slmModemPickerValue.value = '';
+        if (slmModemPickerSearch) slmModemPickerSearch.value = '';
+        if (slmModemPickerClear) slmModemPickerClear.classList.add('hidden');
+    }
 
     // Show/hide fields based on device type
     toggleDetailFields();
+
+    // Check for paired device and show cascade section if applicable
+    checkAndShowCascadeSection();
+}
+
+// Check for paired device and show/hide cascade section
+async function checkAndShowCascadeSection() {
+    const cascadeSection = document.getElementById('detailCascadeSection');
+    const cascadeToUnitId = document.getElementById('detailCascadeToUnitId');
+    const pairedDeviceName = document.getElementById('detailPairedDeviceName');
+
+    if (!cascadeSection) return;
+
+    // Reset cascade section
+    cascadeSection.classList.add('hidden');
+    if (cascadeToUnitId) cascadeToUnitId.value = '';
+    if (pairedDeviceName) pairedDeviceName.textContent = '';
+
+    // Reset checkboxes
+    ['detailCascadeDeployed', 'detailCascadeRetired', 'detailCascadeProject',
+     'detailCascadeLocation', 'detailCascadeCoordinates', 'detailCascadeNote'].forEach(id => {
+        const checkbox = document.getElementById(id);
+        if (checkbox) checkbox.checked = false;
+    });
+
+    let pairedUnitId = null;
+
+    // Check based on device type
+    if (currentUnit.device_type === 'modem' && currentUnit.deployed_with_unit_id) {
+        // Modem is paired with a seismograph or SLM
+        pairedUnitId = currentUnit.deployed_with_unit_id;
+    } else if ((currentUnit.device_type === 'seismograph' || currentUnit.device_type === 'sound_level_meter') && currentUnit.deployed_with_modem_id) {
+        // Seismograph or SLM is paired with a modem
+        pairedUnitId = currentUnit.deployed_with_modem_id;
+    }
+
+    if (pairedUnitId) {
+        // Show cascade section
+        cascadeSection.classList.remove('hidden');
+        if (cascadeToUnitId) cascadeToUnitId.value = pairedUnitId;
+        if (pairedDeviceName) pairedDeviceName.textContent = pairedUnitId;
+    }
 }
 
 // Toggle device-specific fields
@@ -753,6 +963,16 @@ document.getElementById('editForm').addEventListener('submit', async function(e)
     e.preventDefault();
 
     const formData = new FormData(this);
+    const deviceType = formData.get('device_type');
+
+    // Fix: FormData contains both modem picker hidden inputs (seismo and slm).
+    // We need to ensure only the correct one is submitted based on device type.
+    // Delete all deployed_with_modem_id entries and re-add the correct one.
+    const modemId = getCorrectModemPickerValue(deviceType);
+    formData.delete('deployed_with_modem_id');
+    if (modemId) {
+        formData.append('deployed_with_modem_id', modemId);
+    }
 
     try {
         const response = await fetch(`/api/roster/edit/${unitId}`, {
@@ -774,6 +994,19 @@ document.getElementById('editForm').addEventListener('submit', async function(e)
     }
 });
 
+// Get the correct modem picker value based on device type
+function getCorrectModemPickerValue(deviceType) {
+    if (deviceType === 'seismograph') {
+        const picker = document.getElementById('modem-picker-value-detail-seismo');
+        return picker ? picker.value : '';
+    } else if (deviceType === 'sound_level_meter') {
+        const picker = document.getElementById('modem-picker-value-detail-slm');
+        return picker ? picker.value : '';
+    }
+    // Modems don't have a deployed_with_modem_id
+    return '';
+}
+
 // Delete unit
 async function deleteUnit() {
     if (!confirm(`Are you sure you want to PERMANENTLY delete unit ${unitId}?\n\nThis action cannot be undone!`)) {
@@ -1168,8 +1401,239 @@ loadUnitData().then(() => {
     loadPhotos();
     loadUnitHistory();
 });
+
+// ===== Pair Device Modal Functions =====
+let pairModalModems = []; // Cache loaded modems
+let pairModalDeviceType = ''; // Current device type
+
+function openPairDeviceModal(deviceType) {
+    const modal = document.getElementById('pairDeviceModal');
+    const searchInput = document.getElementById('pairModemSearch');
+    const hideBenchedCheckbox = document.getElementById('pairHideBenched');
+
+    if (!modal) return;
+
+    pairModalDeviceType = deviceType;
+
+    // Reset search and filter
+    if (searchInput) searchInput.value = '';
+    if (hideBenchedCheckbox) hideBenchedCheckbox.checked = false;
+
+    // Show modal
+    modal.classList.remove('hidden');
+
+    // Focus search input
+    setTimeout(() => {
+        if (searchInput) searchInput.focus();
+    }, 100);
+
+    // Load available modems
+    loadAvailableModems();
+}
+
+function closePairDeviceModal() {
+    const modal = document.getElementById('pairDeviceModal');
+    if (modal) modal.classList.add('hidden');
+    pairModalModems = [];
+}
+
+async function loadAvailableModems() {
+    const listContainer = document.getElementById('pairModemList');
+    listContainer.innerHTML = '<div class="text-center py-4"><div class="animate-spin inline-block w-6 h-6 border-2 border-seismo-orange border-t-transparent rounded-full"></div><p class="mt-2 text-sm text-gray-500">Loading modems...</p></div>';
+
+    try {
+        const response = await fetch('/api/roster/modems');
+        if (!response.ok) throw new Error('Failed to load modems');
+
+        pairModalModems = await response.json();
+
+        if (pairModalModems.length === 0) {
+            listContainer.innerHTML = '<p class="text-center py-4 text-gray-500">No modems found in roster</p>';
+            return;
+        }
+
+        // Render the list
+        renderModemList();
+    } catch (error) {
+        listContainer.innerHTML = `<p class="text-center py-4 text-red-500">Error: ${error.message}</p>`;
+    }
+}
+
+function filterPairModemList() {
+    renderModemList();
+}
+
+function renderModemList() {
+    const listContainer = document.getElementById('pairModemList');
+    const searchInput = document.getElementById('pairModemSearch');
+    const hideBenchedCheckbox = document.getElementById('pairHideBenched');
+
+    const searchTerm = (searchInput?.value || '').toLowerCase().trim();
+    const hideBenched = hideBenchedCheckbox?.checked || false;
+
+    // Filter modems
+    let filteredModems = pairModalModems.filter(modem => {
+        // Filter by benched status
+        if (hideBenched && !modem.deployed) return false;
+
+        // Filter by search term
+        if (searchTerm) {
+            const searchFields = [
+                modem.id,
+                modem.ip_address || '',
+                modem.phone_number || '',
+                modem.note || ''
+            ].join(' ').toLowerCase();
+            if (!searchFields.includes(searchTerm)) return false;
+        }
+
+        return true;
+    });
+
+    if (filteredModems.length === 0) {
+        listContainer.innerHTML = '<p class="text-center py-4 text-gray-500">No modems match your criteria</p>';
+        return;
+    }
+
+    // Build modem list
+    let html = '';
+    for (const modem of filteredModems) {
+        const displayParts = [modem.id];
+        if (modem.ip_address) displayParts.push(`(${modem.ip_address})`);
+        if (modem.note) displayParts.push(`- ${modem.note.substring(0, 30)}${modem.note.length > 30 ? '...' : ''}`);
+
+        const deployedBadge = modem.deployed
+            ? '<span class="px-2 py-0.5 bg-green-100 dark:bg-green-900/30 text-green-800 dark:text-green-300 text-xs rounded">Deployed</span>'
+            : '<span class="px-2 py-0.5 bg-gray-100 dark:bg-gray-700 text-gray-600 dark:text-gray-400 text-xs rounded">Benched</span>';
+
+        const pairedBadge = modem.deployed_with_unit_id
+            ? `<span class="px-2 py-0.5 bg-purple-100 dark:bg-purple-900/30 text-purple-800 dark:text-purple-300 text-xs rounded">Paired: ${modem.deployed_with_unit_id}</span>`
+            : '';
+
+        html += `
+            <div class="flex items-center justify-between p-3 hover:bg-gray-50 dark:hover:bg-gray-700 cursor-pointer border-b border-gray-100 dark:border-gray-700 last:border-0"
+                 onclick="selectModemForPairing('${modem.id}', '${displayParts.join(' ').replace(/'/g, "\\'")}')">
+                <div class="flex-1">
+                    <div class="font-medium text-gray-900 dark:text-white">
+                        <span class="text-seismo-orange">${modem.id}</span>
+                        ${modem.ip_address ? `<span class="text-gray-400 ml-2 font-mono text-sm">${modem.ip_address}</span>` : ''}
+                    </div>
+                    ${modem.note ? `<div class="text-sm text-gray-500 dark:text-gray-400 truncate">${modem.note}</div>` : ''}
+                </div>
+                <div class="flex gap-2 ml-3">
+                    ${deployedBadge}
+                    ${pairedBadge}
+                </div>
+            </div>
+        `;
+    }
+
+    listContainer.innerHTML = html;
+}
+
+function selectModemForPairing(modemId, displayText) {
+    // Update the correct picker based on device type
+    let pickerId = '';
+    if (pairModalDeviceType === 'seismograph') {
+        pickerId = '-detail-seismo';
+    } else if (pairModalDeviceType === 'sound_level_meter') {
+        pickerId = '-detail-slm';
+    }
+
+    const valueInput = document.getElementById('modem-picker-value' + pickerId);
+    const searchInput = document.getElementById('modem-picker-search' + pickerId);
+    const clearBtn = document.getElementById('modem-picker-clear' + pickerId);
+
+    if (valueInput) valueInput.value = modemId;
+    if (searchInput) searchInput.value = displayText;
+    if (clearBtn) clearBtn.classList.remove('hidden');
+
+    // Close modal
+    closePairDeviceModal();
+}
+
+// Clear pairing (unpair device from modem)
+function clearPairing(deviceType) {
+    let pickerId = '';
+    if (deviceType === 'seismograph') {
+        pickerId = '-detail-seismo';
+    } else if (deviceType === 'sound_level_meter') {
+        pickerId = '-detail-slm';
+    }
+
+    const valueInput = document.getElementById('modem-picker-value' + pickerId);
+    const searchInput = document.getElementById('modem-picker-search' + pickerId);
+    const clearBtn = document.getElementById('modem-picker-clear' + pickerId);
+
+    if (valueInput) valueInput.value = '';
+    if (searchInput) searchInput.value = '';
+    if (clearBtn) clearBtn.classList.add('hidden');
+
+    closePairDeviceModal();
+}
 </script>
 
+<!-- Pair Device Modal -->
+<div id="pairDeviceModal" class="hidden fixed inset-0 z-50 overflow-y-auto">
+    <div class="flex items-center justify-center min-h-screen px-4">
+        <!-- Backdrop -->
+        <div class="fixed inset-0 bg-black/50" onclick="closePairDeviceModal()"></div>
+
+        <!-- Modal Content -->
+        <div class="relative bg-white dark:bg-slate-800 rounded-xl shadow-xl max-w-lg w-full max-h-[80vh] overflow-hidden">
+            <!-- Header -->
+            <div class="flex items-center justify-between px-6 py-4 border-b border-gray-200 dark:border-gray-700">
+                <div>
+                    <h3 class="text-lg font-semibold text-gray-900 dark:text-white">Pair with Modem</h3>
+                    <p class="text-sm text-gray-500 dark:text-gray-400">Select a modem to pair with this device</p>
+                </div>
+                <button onclick="closePairDeviceModal()" class="text-gray-400 hover:text-gray-600 dark:hover:text-gray-300">
+                    <svg class="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                        <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M6 18L18 6M6 6l12 12"></path>
+                    </svg>
+                </button>
+            </div>
+
+            <!-- Search and Filter -->
+            <div class="px-6 py-3 border-b border-gray-200 dark:border-gray-700 bg-gray-50 dark:bg-slate-900/50">
+                <div class="flex gap-3 items-center">
+                    <!-- Search Input -->
+                    <div class="flex-1 relative">
+                        <input type="text"
+                               id="pairModemSearch"
+                               placeholder="Search by ID, IP, or note..."
+                               oninput="filterPairModemList()"
+                               class="w-full px-4 py-2 pl-10 rounded-lg border border-gray-300 dark:border-gray-600 bg-white dark:bg-slate-700 text-gray-900 dark:text-white focus:ring-2 focus:ring-seismo-orange focus:border-seismo-orange text-sm">
+                        <svg class="w-5 h-5 text-gray-400 absolute left-3 top-1/2 -translate-y-1/2" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0z"></path>
+                        </svg>
+                    </div>
+                    <!-- Hide Benched Toggle -->
+                    <label class="flex items-center gap-2 cursor-pointer whitespace-nowrap">
+                        <input type="checkbox"
+                               id="pairHideBenched"
+                               onchange="filterPairModemList()"
+                               class="w-4 h-4 text-seismo-orange focus:ring-seismo-orange rounded">
+                        <span class="text-sm text-gray-600 dark:text-gray-400">Deployed only</span>
+                    </label>
+                </div>
+            </div>
+
+            <!-- Modem List -->
+            <div id="pairModemList" class="max-h-80 overflow-y-auto">
+                <!-- Populated by JavaScript -->
+            </div>
+
+            <!-- Footer -->
+            <div class="px-6 py-4 border-t border-gray-200 dark:border-gray-700 bg-gray-50 dark:bg-slate-900">
+                <button onclick="closePairDeviceModal()" class="w-full px-4 py-2 bg-gray-200 dark:bg-gray-700 hover:bg-gray-300 dark:hover:bg-gray-600 text-gray-700 dark:text-gray-300 rounded-lg transition-colors">
+                    Cancel
+                </button>
+            </div>
+        </div>
+    </div>
+</div>
+
 <!-- Include Project Create Modal for inline project creation -->
 {% include "partials/project_create_modal.html" %}