diff --git a/backend/routers/slm_dashboard.py b/backend/routers/slm_dashboard.py
index 3d9c0df..bcfe057 100644
--- a/backend/routers/slm_dashboard.py
+++ b/backend/routers/slm_dashboard.py
@@ -6,7 +6,7 @@ Provides API endpoints for the Sound Level Meters dashboard page.
 
 from fastapi import APIRouter, Request, Depends, Query
 from fastapi.templating import Jinja2Templates
-from fastapi.responses import HTMLResponse
+from fastapi.responses import HTMLResponse, JSONResponse
 from sqlalchemy.orm import Session
 from sqlalchemy import func
 from datetime import datetime, timedelta
@@ -60,14 +60,20 @@ async def get_slm_stats(request: Request, db: Session = Depends(get_db)):
 async def get_slm_units(
     request: Request,
     db: Session = Depends(get_db),
-    search: str = Query(None)
+    search: str = Query(None),
+    project: str = Query(None)
 ):
     """
     Get list of SLM units for the sidebar.
     Returns HTML partial with unit cards.
+    Supports filtering by search term and project.
     """
     query = db.query(RosterUnit).filter_by(device_type="sound_level_meter")
 
+    # Filter by project if provided
+    if project:
+        query = query.filter(RosterUnit.project_id == project)
+
     # Filter by search term if provided
     if search:
         search_term = f"%{search}%"
@@ -326,3 +332,55 @@ async def test_modem_connection(modem_id: str, db: Session = Depends(get_db)):
             "modem_id": modem_id,
             "detail": str(e)
         }
+
+
+@router.get("/diagnostics/{unit_id}", response_class=HTMLResponse)
+async def get_diagnostics(request: Request, unit_id: str, db: Session = Depends(get_db)):
+    """
+    Get compact diagnostics card for a specific SLM unit.
+    Returns HTML partial with key metrics only.
+    """
+    unit = db.query(RosterUnit).filter_by(id=unit_id, device_type="sound_level_meter").first()
+
+    if not unit:
+        return HTMLResponse(
+            content='<div class="p-6 text-center text-red-600">Unit not found</div>',
+            status_code=404
+        )
+
+    # Get modem info
+    modem = None
+    modem_ip = None
+    if unit.deployed_with_modem_id:
+        modem = db.query(RosterUnit).filter_by(id=unit.deployed_with_modem_id, device_type="modem").first()
+        if modem:
+            # Try modem_rx_host first (if it exists), then fall back to ip_address
+            modem_ip = getattr(modem, 'modem_rx_host', None) or modem.ip_address
+    elif unit.slm_host:
+        modem_ip = unit.slm_host
+
+    return templates.TemplateResponse("partials/slm_diagnostics_card.html", {
+        "request": request,
+        "unit": unit,
+        "modem": modem,
+        "modem_ip": modem_ip
+    })
+
+
+@router.get("/projects")
+async def get_projects(db: Session = Depends(get_db)):
+    """
+    Get list of unique projects from deployed SLMs.
+    Returns JSON array of project names.
+    """
+    projects = db.query(RosterUnit.project_id).filter(
+        RosterUnit.device_type == "sound_level_meter",
+        RosterUnit.deployed == True,
+        RosterUnit.retired == False,
+        RosterUnit.project_id.isnot(None)
+    ).distinct().order_by(RosterUnit.project_id).all()
+
+    # Extract project names from query result tuples
+    project_list = [p[0] for p in projects if p[0]]
+
+    return JSONResponse(content={"projects": project_list})
diff --git a/templates/partials/slm_diagnostics_card.html b/templates/partials/slm_diagnostics_card.html
new file mode 100644
index 0000000..b5a77a8
--- /dev/null
+++ b/templates/partials/slm_diagnostics_card.html
@@ -0,0 +1,206 @@
+<!-- Compact Diagnostics Card for {{ unit.id }} -->
+<div class="h-full flex flex-col p-6">
+    <!-- Header -->
+    <div class="flex items-center justify-between mb-6">
+        <div>
+            <h2 class="text-2xl font-bold text-gray-900 dark:text-white">{{ unit.id }}</h2>
+            <p class="text-sm text-gray-600 dark:text-gray-400">
+                {% if unit.slm_model %}{{ unit.slm_model }}{% endif %}
+                {% if unit.slm_serial_number %} • S/N: {{ unit.slm_serial_number }}{% endif %}
+            </p>
+        </div>
+
+        <!-- Status Badge -->
+        <span id="diag-status-badge" class="px-4 py-2 bg-gray-200 dark:bg-gray-700 text-gray-700 dark:text-gray-300 rounded-lg font-medium">
+            Loading...
+        </span>
+    </div>
+
+    <!-- Connection Status -->
+    <div class="bg-white dark:bg-gray-800 rounded-lg p-4 border border-gray-200 dark:border-gray-700 mb-4">
+        <div class="flex items-center justify-between">
+            <div class="flex items-center">
+                <svg class="w-5 h-5 text-gray-500 mr-2" fill="currentColor" viewBox="0 0 20 20">
+                    <path fill-rule="evenodd" d="M5.05 3.636a1 1 0 010 1.414 7 7 0 000 9.9 1 1 0 11-1.414 1.414 9 9 0 010-12.728 1 1 0 011.414 0zm9.9 0a1 1 0 011.414 0 9 9 0 010 12.728 1 1 0 11-1.414-1.414 7 7 0 000-9.9 1 1 0 010-1.414zM7.879 6.464a1 1 0 010 1.414 3 3 0 000 4.243 1 1 0 11-1.415 1.414 5 5 0 010-7.07 1 1 0 011.415 0zm4.242 0a1 1 0 011.415 0 5 5 0 010 7.072 1 1 0 01-1.415-1.415 3 3 0 000-4.242 1 1 0 010-1.415zM10 9a1 1 0 011 1v.01a1 1 0 11-2 0V10a1 1 0 011-1z" clip-rule="evenodd"/>
+                </svg>
+                <span class="text-sm font-medium text-gray-700 dark:text-gray-300">Connection</span>
+            </div>
+            <div>
+                {% if modem %}
+                    <span class="text-sm text-gray-600 dark:text-gray-400">via {{ modem.id }}</span>
+                {% elif modem_ip %}
+                    <span class="text-sm text-gray-600 dark:text-gray-400">Direct: {{ modem_ip }}</span>
+                {% else %}
+                    <span class="text-sm text-red-600 dark:text-red-400">Not configured</span>
+                {% endif %}
+                <span id="connection-status" class="ml-2 w-2 h-2 bg-gray-400 rounded-full inline-block"></span>
+            </div>
+        </div>
+    </div>
+
+    <!-- Current Sound Levels -->
+    <div class="grid grid-cols-2 gap-3 mb-4">
+        <div class="bg-blue-50 dark:bg-blue-900/20 rounded-lg p-4">
+            <p class="text-xs text-gray-600 dark:text-gray-400 mb-1">Lp (Instant)</p>
+            <p id="diag-lp" class="text-2xl font-bold text-blue-600 dark:text-blue-400">--</p>
+            <p class="text-xs text-gray-500 dark:text-gray-400">dB</p>
+        </div>
+
+        <div class="bg-green-50 dark:bg-green-900/20 rounded-lg p-4">
+            <p class="text-xs text-gray-600 dark:text-gray-400 mb-1">Leq (Average)</p>
+            <p id="diag-leq" class="text-2xl font-bold text-green-600 dark:text-green-400">--</p>
+            <p class="text-xs text-gray-500 dark:text-gray-400">dB</p>
+        </div>
+
+        <div class="bg-red-50 dark:bg-red-900/20 rounded-lg p-4">
+            <p class="text-xs text-gray-600 dark:text-gray-400 mb-1">Lmax (Max)</p>
+            <p id="diag-lmax" class="text-2xl font-bold text-red-600 dark:text-red-400">--</p>
+            <p class="text-xs text-gray-500 dark:text-gray-400">dB</p>
+        </div>
+
+        <div class="bg-purple-50 dark:bg-purple-900/20 rounded-lg p-4">
+            <p class="text-xs text-gray-600 dark:text-gray-400 mb-1">Lmin (Min)</p>
+            <p id="diag-lmin" class="text-2xl font-bold text-purple-600 dark:text-purple-400">--</p>
+            <p class="text-xs text-gray-500 dark:text-gray-400">dB</p>
+        </div>
+    </div>
+
+    <!-- Battery and Power -->
+    <div class="grid grid-cols-2 gap-3 mb-4">
+        <div class="bg-white dark:bg-gray-800 rounded-lg p-4 border border-gray-200 dark:border-gray-700">
+            <div class="flex items-center justify-between mb-2">
+                <span class="text-xs text-gray-600 dark:text-gray-400">Battery</span>
+                <svg class="w-4 h-4 text-gray-500" fill="currentColor" viewBox="0 0 20 20">
+                    <path d="M6 2a2 2 0 00-2 2v12a2 2 0 002 2h8a2 2 0 002-2V4a2 2 0 00-2-2H6zm0 2h8v12H6V4zm7 2a1 1 0 011 1v6a1 1 0 11-2 0V7a1 1 0 011-1z"/>
+                </svg>
+            </div>
+            <div id="diag-battery-level" class="text-xl font-bold text-gray-900 dark:text-white">--</div>
+            <div class="mt-2 bg-gray-200 dark:bg-gray-700 rounded-full h-2">
+                <div id="diag-battery-bar" class="bg-gray-400 h-2 rounded-full transition-all" style="width: 0%"></div>
+            </div>
+        </div>
+
+        <div class="bg-white dark:bg-gray-800 rounded-lg p-4 border border-gray-200 dark:border-gray-700">
+            <div class="flex items-center justify-between mb-2">
+                <span class="text-xs text-gray-600 dark:text-gray-400">Power</span>
+                <svg class="w-4 h-4 text-gray-500" fill="currentColor" viewBox="0 0 20 20">
+                    <path fill-rule="evenodd" d="M11.3 1.046A1 1 0 0112 2v5h4a1 1 0 01.82 1.573l-7 10A1 1 0 018 18v-5H4a1 1 0 01-.82-1.573l7-10a1 1 0 011.12-.38z" clip-rule="evenodd"/>
+                </svg>
+            </div>
+            <div id="diag-power-source" class="text-lg font-semibold text-gray-900 dark:text-white">--</div>
+        </div>
+    </div>
+
+    <!-- Last Check-in -->
+    <div class="bg-white dark:bg-gray-800 rounded-lg p-4 border border-gray-200 dark:border-gray-700 mb-6">
+        <div class="flex items-center justify-between">
+            <div class="flex items-center">
+                <svg class="w-5 h-5 text-gray-500 mr-2" fill="currentColor" viewBox="0 0 20 20">
+                    <path fill-rule="evenodd" d="M10 18a8 8 0 100-16 8 8 0 000 16zm1-12a1 1 0 10-2 0v4a1 1 0 00.293.707l2.828 2.829a1 1 0 101.415-1.415L11 9.586V6z" clip-rule="evenodd"/>
+                </svg>
+                <span class="text-sm font-medium text-gray-700 dark:text-gray-300">Last Check-in</span>
+            </div>
+            <div>
+                {% if unit.slm_last_check %}
+                    <span class="text-sm text-gray-600 dark:text-gray-400">{{ unit.slm_last_check.strftime('%Y-%m-%d %H:%M:%S') }}</span>
+                {% else %}
+                    <span class="text-sm text-gray-500 dark:text-gray-500">Never</span>
+                {% endif %}
+            </div>
+        </div>
+    </div>
+
+    <!-- Open Command Center Button -->
+    <div class="mt-auto">
+        <button onclick="openCommandCenter('{{ unit.id }}')"
+                class="w-full px-6 py-3 bg-seismo-orange hover:bg-orange-600 text-white rounded-lg font-medium flex items-center justify-center transition-colors">
+            <svg class="w-5 h-5 mr-2" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 19V6l12-3v13M9 19c0 1.105-1.343 2-3 2s-3-.895-3-2 1.343-2 3-2 3 .895 3 2zm12-3c0 1.105-1.343 2-3 2s-3-.895-3-2 1.343-2 3-2 3 .895 3 2zM9 10l12-3"/>
+            </svg>
+            Open Command Center
+        </button>
+    </div>
+</div>
+
+<script>
+(function() {
+    const diagUnitId = '{{ unit.id }}';
+
+    // Clear any existing connections before starting new ones
+    window.SLMConnectionManager.setCurrentUnit(diagUnitId);
+
+    function updateDiagnosticsData() {
+        fetch(`/api/slmm/${diagUnitId}/live`)
+            .then(response => response.json())
+            .then(result => {
+                if (result.status === 'ok' && result.data) {
+                    const data = result.data;
+
+                    // Update status badge
+                    const statusBadge = document.getElementById('diag-status-badge');
+                    if (statusBadge) {
+                        const isMeasuring = data.measurement_state === 'Start';
+                        if (isMeasuring) {
+                            statusBadge.className = 'px-4 py-2 bg-green-100 dark:bg-green-900/30 text-green-800 dark:text-green-400 rounded-lg font-medium flex items-center';
+                            statusBadge.innerHTML = '<span class="w-2 h-2 bg-green-500 rounded-full mr-2 animate-pulse"></span>Measuring';
+                        } else {
+                            statusBadge.className = 'px-4 py-2 bg-gray-200 dark:bg-gray-700 text-gray-700 dark:text-gray-300 rounded-lg font-medium';
+                            statusBadge.textContent = 'Stopped';
+                        }
+                    }
+
+                    // Update sound levels
+                    ['lp', 'leq', 'lmax', 'lmin'].forEach(metric => {
+                        const el = document.getElementById(`diag-${metric}`);
+                        if (el) el.textContent = data[metric] || '--';
+                    });
+
+                    // Update battery
+                    const batteryEl = document.getElementById('diag-battery-level');
+                    const batteryBar = document.getElementById('diag-battery-bar');
+                    if (batteryEl && data.battery_level) {
+                        const level = parseInt(data.battery_level);
+                        batteryEl.textContent = `${level}%`;
+
+                        if (batteryBar) {
+                            batteryBar.style.width = `${level}%`;
+                            if (level > 50) {
+                                batteryBar.className = 'bg-green-500 h-2 rounded-full transition-all';
+                            } else if (level > 20) {
+                                batteryBar.className = 'bg-yellow-500 h-2 rounded-full transition-all';
+                            } else {
+                                batteryBar.className = 'bg-red-500 h-2 rounded-full transition-all';
+                            }
+                        }
+                    }
+
+                    // Update power source
+                    const powerEl = document.getElementById('diag-power-source');
+                    if (powerEl) powerEl.textContent = data.power_source || '--';
+
+                    // Update connection status
+                    const connStatus = document.getElementById('connection-status');
+                    if (connStatus) {
+                        connStatus.className = 'ml-2 w-2 h-2 bg-green-500 rounded-full inline-block';
+                    }
+                }
+            })
+            .catch(error => {
+                console.error('Failed to refresh diagnostics:', error);
+                const connStatus = document.getElementById('connection-status');
+                if (connStatus) {
+                    connStatus.className = 'ml-2 w-2 h-2 bg-red-500 rounded-full inline-block';
+                }
+            });
+    }
+
+    // Initial update
+    updateDiagnosticsData();
+
+    // Set up refresh interval and register it
+    const interval = setInterval(updateDiagnosticsData, 10000);
+    window.SLMConnectionManager.registerInterval(interval);
+
+    console.log(`Diagnostics card for ${diagUnitId} initialized`);
+})();
+</script>
diff --git a/templates/partials/slm_live_view.html b/templates/partials/slm_live_view.html
index 54e2560..b1b11f8 100644
--- a/templates/partials/slm_live_view.html
+++ b/templates/partials/slm_live_view.html
@@ -686,8 +686,13 @@ async function controlUnit(unitId, action) {
 if (typeof window.refreshInterval === 'undefined') {
     window.refreshInterval = null;
 }
-const REFRESH_INTERVAL_MS = 30000; // 30 seconds
-const unit_id = '{{ unit.id }}';
+if (typeof window.REFRESH_INTERVAL_MS === 'undefined') {
+    window.REFRESH_INTERVAL_MS = 30000; // 30 seconds
+}
+if (typeof window.unit_id === 'undefined' || window.unit_id !== '{{ unit.id }}') {
+    // Keep HTMX reloads from reusing the old unit id
+    window.unit_id = '{{ unit.id }}';
+}
 
 function updateDeviceStatus() {
     fetch(`/api/slmm/${unit_id}/live`)
@@ -755,7 +760,7 @@ function startAutoRefresh() {
     updateDeviceStatus();
 
     // Set up interval
-    refreshInterval = setInterval(updateDeviceStatus, REFRESH_INTERVAL_MS);
+    refreshInterval = setInterval(updateDeviceStatus, window.REFRESH_INTERVAL_MS);
     console.log('Auto-refresh started (30s interval)');
 }
 
@@ -778,6 +783,12 @@ if (typeof window.timerInterval === 'undefined') {
     window.timerInterval = null;
     window.measurementStartTime = null;  // ISO string from backend
 }
+if (typeof window.timerSource === 'undefined') {
+    window.timerSource = null;
+}
+if (typeof window.lastFtpErrorTime === 'undefined') {
+    window.lastFtpErrorTime = null;
+}
 
 // Format elapsed time as HH:MM:SS
 function formatElapsedTime(milliseconds) {
@@ -818,42 +829,52 @@ function updateTimerDisplay() {
 async function syncTimerWithBackend(measurementState, measurementStartTime) {
     // Device returns "Start" when measuring, "Stop" when stopped
     const isMeasuring = measurementState === 'Start';
+    const now = Date.now();
 
     if (isMeasuring && measurementStartTime) {
         // Measurement is running - check both backend and FTP timestamps
         // Use whichever is earlier (older = actual measurement start)
 
         // First check FTP for potentially older timestamp
-        try {
-            const response = await fetch(`/api/slmm/${unit_id}/ftp/latest-measurement-time`);
-            const result = await response.json();
-
-            if (result.status === 'ok' && result.latest_timestamp) {
-                const backendTime = new Date(measurementStartTime + 'Z');
-                const ftpTime = new Date(result.latest_timestamp + 'Z');
-
-                // Use the earlier timestamp (represents actual measurement start)
-                if (ftpTime < backendTime) {
-                    window.measurementStartTime = result.latest_timestamp;
-                    window.timerSource = 'ftp';
-                    console.log('Timer synced with FTP folder (earlier):', result.latest_folder, '@', result.latest_timestamp);
-                } else {
-                    window.measurementStartTime = measurementStartTime;
-                    window.timerSource = 'backend';
-                    console.log('Timer synced with backend state (earlier):', measurementStartTime);
-                }
-            } else {
-                // No FTP timestamp, use backend
-                window.measurementStartTime = measurementStartTime;
-                window.timerSource = 'backend';
-                console.log('Timer synced with backend state:', measurementStartTime);
-            }
-        } catch (error) {
-            console.error('Failed to check FTP timestamp:', error);
-            // Fallback to backend on error
+        const shouldSkipFtp = window.lastFtpErrorTime && (now - window.lastFtpErrorTime < 10000);
+        if (shouldSkipFtp) {
             window.measurementStartTime = measurementStartTime;
             window.timerSource = 'backend';
-            console.log('Timer synced with backend state (FTP check failed):', measurementStartTime);
+            console.log('Timer using backend state (skipping FTP due to recent error):', measurementStartTime);
+        } else {
+            try {
+                const response = await fetch(`/api/slmm/${unit_id}/ftp/latest-measurement-time`);
+                const result = await response.json();
+
+                if (result.status === 'ok' && result.latest_timestamp) {
+                    const backendTime = new Date(measurementStartTime + 'Z');
+                    const ftpTime = new Date(result.latest_timestamp + 'Z');
+
+                    // Use the earlier timestamp (represents actual measurement start)
+                    if (ftpTime < backendTime) {
+                        window.measurementStartTime = result.latest_timestamp;
+                        window.timerSource = 'ftp';
+                        console.log('Timer synced with FTP folder (earlier):', result.latest_folder, '@', result.latest_timestamp);
+                    } else {
+                        window.measurementStartTime = measurementStartTime;
+                        window.timerSource = 'backend';
+                        console.log('Timer synced with backend state (earlier):', measurementStartTime);
+                    }
+                    window.lastFtpErrorTime = null;
+                } else {
+                    // No FTP timestamp, use backend
+                    window.measurementStartTime = measurementStartTime;
+                    window.timerSource = 'backend';
+                    console.log('Timer synced with backend state:', measurementStartTime);
+                }
+            } catch (error) {
+                console.error('Failed to check FTP timestamp:', error);
+                window.lastFtpErrorTime = now;
+                // Fallback to backend on error
+                window.measurementStartTime = measurementStartTime;
+                window.timerSource = 'backend';
+                console.log('Timer synced with backend state (FTP check failed):', measurementStartTime);
+            }
         }
 
         // Start interval if not already running
@@ -869,27 +890,34 @@ async function syncTimerWithBackend(measurementState, measurementStartTime) {
         // Try FTP fallback to get measurement start from latest folder timestamp
         if (!window.measurementStartTime || window.timerSource !== 'ftp') {
             console.log('Device measuring but no backend start time - checking FTP fallback...');
-            try {
-                const response = await fetch(`/api/slmm/${unit_id}/ftp/latest-measurement-time`);
-                const result = await response.json();
+            const skipFtp = window.lastFtpErrorTime && (Date.now() - window.lastFtpErrorTime < 10000);
+            if (!skipFtp) {
+                try {
+                    const response = await fetch(`/api/slmm/${unit_id}/ftp/latest-measurement-time`);
+                    const result = await response.json();
 
-                if (result.status === 'ok' && result.latest_timestamp) {
-                    window.measurementStartTime = result.latest_timestamp;
-                    window.timerSource = 'ftp';
-                    console.log('Timer synced with FTP folder:', result.latest_folder, '@', result.latest_timestamp);
+                    if (result.status === 'ok' && result.latest_timestamp) {
+                        window.measurementStartTime = result.latest_timestamp;
+                        window.timerSource = 'ftp';
+                        console.log('Timer synced with FTP folder:', result.latest_folder, '@', result.latest_timestamp);
 
-                    // Start timer interval if not already running
-                    if (!window.timerInterval) {
-                        window.timerInterval = setInterval(updateTimerDisplay, 1000);
-                        console.log('Timer display started (FTP source)');
+                        // Start timer interval if not already running
+                        if (!window.timerInterval) {
+                            window.timerInterval = setInterval(updateTimerDisplay, 1000);
+                            console.log('Timer display started (FTP source)');
+                        }
+
+                        updateTimerDisplay();
+                        window.lastFtpErrorTime = null;
+                    } else {
+                        console.log('No FTP timestamp available');
                     }
-
-                    updateTimerDisplay();
-                } else {
-                    console.log('No FTP timestamp available');
+                } catch (error) {
+                    console.error('Failed to get FTP timestamp:', error);
+                    window.lastFtpErrorTime = Date.now();
                 }
-            } catch (error) {
-                console.error('Failed to get FTP timestamp:', error);
+            } else {
+                console.log('Skipping FTP fallback due to recent error');
             }
         }
     } else {
diff --git a/templates/sound_level_meters.html b/templates/sound_level_meters.html
index 0e48b7d..b00f27e 100644
--- a/templates/sound_level_meters.html
+++ b/templates/sound_level_meters.html
@@ -28,14 +28,28 @@
             <h2 class="text-xl font-semibold text-gray-900 dark:text-white mb-4">Active Units</h2>
 
             <!-- Search/Filter -->
-            <div class="mb-4">
-                <input type="text"
+            <div class="mb-4 space-y-2">
+                <!-- Project Filter -->
+                <select id="project-filter"
+                        name="project"
+                        class="w-full px-4 py-2 border border-gray-300 dark:border-gray-600 rounded-lg bg-white dark:bg-gray-700 text-gray-900 dark:text-white"
+                        hx-get="/api/slm-dashboard/units"
+                        hx-trigger="change"
+                        hx-target="#slm-list"
+                        hx-include="#search-input, #project-filter">
+                    <option value="">All Projects</option>
+                    <!-- Will be populated dynamically -->
+                </select>
+
+                <!-- Search Input -->
+                <input id="search-input"
+                       type="text"
                        placeholder="Search units..."
                        class="w-full px-4 py-2 border border-gray-300 dark:border-gray-600 rounded-lg bg-white dark:bg-gray-700 text-gray-900 dark:text-white"
                        hx-get="/api/slm-dashboard/units"
                        hx-trigger="keyup changed delay:300ms"
                        hx-target="#slm-list"
-                       hx-include="this"
+                       hx-include="#search-input, #project-filter"
                        name="search">
             </div>
 
@@ -93,9 +107,94 @@
     </div>
 </div>
 
+<!-- Command Center Modal -->
+<div id="command-center-modal" class="hidden fixed inset-0 bg-black bg-opacity-50 z-50">
+    <div class="flex items-center justify-center min-h-screen p-4">
+        <div class="bg-white dark:bg-gray-900 rounded-lg shadow-xl w-full max-w-7xl max-h-[90vh] overflow-y-auto">
+            <div class="sticky top-0 bg-white dark:bg-gray-900 border-b border-gray-200 dark:border-gray-700 px-6 py-4 flex items-center justify-between z-10">
+                <h2 class="text-xl font-bold text-gray-900 dark:text-white">Command Center</h2>
+                <button onclick="closeCommandCenter()" class="text-gray-500 hover:text-gray-700 dark:text-gray-400 dark:hover:text-gray-200">
+                    <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"/>
+                    </svg>
+                </button>
+            </div>
+            <div id="command-center-content" class="p-6">
+                <!-- Command center will load here -->
+            </div>
+        </div>
+    </div>
+</div>
+
 <script>
-// Function to select a unit and load live view
+// Global Connection Manager - ensures only one SLM connection at a time
+window.SLMConnectionManager = {
+    activeIntervals: [],
+    activeWebSocket: null,
+    currentUnitId: null,
+
+    // Clear all existing connections
+    clearAll: function() {
+        console.log('SLMConnectionManager: Clearing all connections');
+
+        // Clear all intervals
+        this.activeIntervals.forEach(interval => {
+            clearInterval(interval);
+        });
+        this.activeIntervals = [];
+
+        // Close WebSocket if exists
+        if (this.activeWebSocket) {
+            this.activeWebSocket.close();
+            this.activeWebSocket = null;
+        }
+
+        // Clear any global intervals that might exist
+        if (window.refreshInterval) {
+            clearInterval(window.refreshInterval);
+            window.refreshInterval = null;
+        }
+        if (window.timerInterval) {
+            clearInterval(window.timerInterval);
+            window.timerInterval = null;
+        }
+        if (window.diagRefreshInterval) {
+            clearInterval(window.diagRefreshInterval);
+            window.diagRefreshInterval = null;
+        }
+
+        console.log('SLMConnectionManager: All connections cleared');
+    },
+
+    // Register a new interval
+    registerInterval: function(intervalId) {
+        this.activeIntervals.push(intervalId);
+    },
+
+    // Register WebSocket
+    registerWebSocket: function(ws) {
+        if (this.activeWebSocket) {
+            this.activeWebSocket.close();
+        }
+        this.activeWebSocket = ws;
+    },
+
+    // Set current unit
+    setCurrentUnit: function(unitId) {
+        if (this.currentUnitId !== unitId) {
+            this.clearAll();
+            this.currentUnitId = unitId;
+        }
+    }
+};
+
+// Function to select a unit and load DIAGNOSTICS CARD (not full command center)
 function selectUnit(unitId) {
+    console.log(`Selecting unit: ${unitId}`);
+
+    // Clear all existing connections
+    window.SLMConnectionManager.clearAll();
+
     // Remove active state from all items
     document.querySelectorAll('.slm-unit-item').forEach(item => {
         item.classList.remove('bg-seismo-orange', 'text-white');
@@ -106,18 +205,58 @@ function selectUnit(unitId) {
     event.currentTarget.classList.remove('bg-gray-100', 'dark:bg-gray-700');
     event.currentTarget.classList.add('bg-seismo-orange', 'text-white');
 
-    // Load live view for this unit
-    htmx.ajax('GET', `/api/slm-dashboard/live-view/${unitId}`, {
+    // Load DIAGNOSTICS CARD (not full live view)
+    htmx.ajax('GET', `/api/slm-dashboard/diagnostics/${unitId}`, {
         target: '#live-view-panel',
         swap: 'innerHTML'
     });
 }
 
+// Open command center in modal
+function openCommandCenter(unitId) {
+    console.log(`Opening command center for: ${unitId}`);
+
+    // Clear diagnostics refresh before opening modal
+    window.SLMConnectionManager.clearAll();
+
+    const modal = document.getElementById('command-center-modal');
+    modal.classList.remove('hidden');
+
+    // Load full command center
+    htmx.ajax('GET', `/api/slm-dashboard/live-view/${unitId}`, {
+        target: '#command-center-content',
+        swap: 'innerHTML'
+    });
+}
+
+// Close command center modal
+function closeCommandCenter() {
+    console.log('Closing command center');
+
+    // Clear all command center connections
+    window.SLMConnectionManager.clearAll();
+
+    document.getElementById('command-center-modal').classList.add('hidden');
+
+    // Reload the diagnostics card for the currently selected unit
+    const activeUnit = document.querySelector('.slm-unit-item.bg-seismo-orange');
+    if (activeUnit) {
+        const unitIdMatch = activeUnit.getAttribute('onclick').match(/selectUnit\('(.+?)'\)/);
+        if (unitIdMatch) {
+            const unitId = unitIdMatch[1];
+            htmx.ajax('GET', `/api/slm-dashboard/diagnostics/${unitId}`, {
+                target: '#live-view-panel',
+                swap: 'innerHTML'
+            });
+        }
+    }
+}
+
 // Configuration modal functions
 function openConfigModal(unitId) {
     const modal = document.getElementById('config-modal');
     modal.classList.remove('hidden');
-    
+
     // Load configuration form via HTMX
     htmx.ajax('GET', `/api/slm-dashboard/config/${unitId}`, {
         target: '#config-modal-content',
@@ -129,121 +268,48 @@ function closeConfigModal() {
     document.getElementById('config-modal').classList.add('hidden');
 }
 
-// Close modal on escape key
+// Close modals on escape key
 document.addEventListener('keydown', function(e) {
     if (e.key === 'Escape') {
         closeConfigModal();
+        closeCommandCenter();
     }
 });
 
-// Close modal when clicking outside
+// Close modals when clicking outside
 document.getElementById('config-modal')?.addEventListener('click', function(e) {
     if (e.target === this) {
         closeConfigModal();
     }
 });
 
-// Initialize WebSocket for selected unit
-let currentWebSocket = null;
-
-function initLiveDataStream(unitId) {
-    // Close existing connection if any
-    if (currentWebSocket) {
-        currentWebSocket.close();
+document.getElementById('command-center-modal')?.addEventListener('click', function(e) {
+    if (e.target === this) {
+        closeCommandCenter();
     }
+});
 
-    // WebSocket URL for SLMM backend via proxy
-    const wsProtocol = window.location.protocol === 'https:' ? 'wss:' : 'ws:';
-    const wsUrl = `${wsProtocol}//${window.location.host}/api/slmm/${unitId}/live`;
-
-    currentWebSocket = new WebSocket(wsUrl);
-
-    currentWebSocket.onopen = function() {
-        console.log('WebSocket connected');
-        // Toggle button visibility
-        const startBtn = document.getElementById('start-stream-btn');
-        const stopBtn = document.getElementById('stop-stream-btn');
-        if (startBtn) startBtn.style.display = 'none';
-        if (stopBtn) stopBtn.style.display = 'flex';
-    };
-
-    currentWebSocket.onmessage = function(event) {
-        const data = JSON.parse(event.data);
-        updateLiveChart(data);
-        updateLiveMetrics(data);
-    };
-
-    currentWebSocket.onerror = function(error) {
-        console.error('WebSocket error:', error);
-    };
-
-    currentWebSocket.onclose = function() {
-        console.log('WebSocket closed');
-        // Toggle button visibility
-        const startBtn = document.getElementById('start-stream-btn');
-        const stopBtn = document.getElementById('stop-stream-btn');
-        if (startBtn) startBtn.style.display = 'flex';
-        if (stopBtn) stopBtn.style.display = 'none';
-    };
-}
-
-function stopLiveDataStream() {
-    if (currentWebSocket) {
-        currentWebSocket.close();
-        currentWebSocket = null;
-    }
-}
-
-// Update live chart with new data point
-let chartData = {
-    timestamps: [],
-    lp: [],
-    leq: []
-};
-
-function updateLiveChart(data) {
-    const now = new Date();
-    chartData.timestamps.push(now.toLocaleTimeString());
-    chartData.lp.push(parseFloat(data.lp || 0));
-    chartData.leq.push(parseFloat(data.leq || 0));
-
-    // Keep only last 60 data points (1 minute at 1 sample/sec)
-    if (chartData.timestamps.length > 60) {
-        chartData.timestamps.shift();
-        chartData.lp.shift();
-        chartData.leq.shift();
-    }
-
-    // Update chart (using Chart.js if available)
-    if (window.liveChart) {
-        window.liveChart.data.labels = chartData.timestamps;
-        window.liveChart.data.datasets[0].data = chartData.lp;
-        window.liveChart.data.datasets[1].data = chartData.leq;
-        window.liveChart.update('none'); // Update without animation for smooth real-time
-    }
-}
-
-function updateLiveMetrics(data) {
-    // Update metric displays
-    if (document.getElementById('live-lp')) {
-        document.getElementById('live-lp').textContent = data.lp || '--';
-    }
-    if (document.getElementById('live-leq')) {
-        document.getElementById('live-leq').textContent = data.leq || '--';
-    }
-    if (document.getElementById('live-lmax')) {
-        document.getElementById('live-lmax').textContent = data.lmax || '--';
-    }
-    if (document.getElementById('live-lmin')) {
-        document.getElementById('live-lmin').textContent = data.lmin || '--';
-    }
-}
+// Load projects for filter dropdown on page load
+document.addEventListener('DOMContentLoaded', function() {
+    fetch('/api/slm-dashboard/projects')
+        .then(response => response.json())
+        .then(data => {
+            const projectFilter = document.getElementById('project-filter');
+            if (projectFilter && data.projects) {
+                data.projects.forEach(project => {
+                    const option = document.createElement('option');
+                    option.value = project;
+                    option.textContent = project;
+                    projectFilter.appendChild(option);
+                });
+            }
+        })
+        .catch(error => console.error('Failed to load projects:', error));
+});
 
 // Cleanup on page unload
 window.addEventListener('beforeunload', function() {
-    if (currentWebSocket) {
-        currentWebSocket.close();
-    }
+    window.SLMConnectionManager.clearAll();
 });
 </script>
 {% endblock %}