slmm/FEATURE_SUMMARY.md

Feature Summary: Device Settings Verification

What Was Added

A new API endpoint that retrieves all current device settings in a single request, allowing users to quickly verify the NL43/NL53 configuration before starting measurements.

New Endpoint

GET /api/nl43/{unit_id}/settings

Returns comprehensive device configuration including:

• Measurement state and weighting settings
• Timing and interval configuration
• Battery level and device clock
• Sleep mode and FTP status

Files Modified

1. app/routers.py

Lines: 728-761

Added new route handler get_all_settings() that:

• Validates device configuration exists
• Checks TCP communication is enabled
• Calls NL43Client.get_all_settings()
• Returns formatted JSON response with all settings
• Handles connection errors, timeouts, and exceptions

2. README.md

Updated sections:

• Line 134: Added new endpoint to Measurement Settings table
• Lines 259-283: Added usage example showing how to verify device settings

Files Created

1. test_settings_endpoint.py

Test/demonstration script showing:

• How to use the get_all_settings() method
• Example API endpoint usage with curl
• Expected response format

2. SETTINGS_ENDPOINT.md

Comprehensive documentation including:

• Detailed endpoint description
• Complete list of settings retrieved
• Usage examples in bash, Python, and JavaScript
• Performance considerations
• Best practices and troubleshooting

3. FEATURE_SUMMARY.md

This file - summary of changes for reference

Existing Functionality Used

The implementation leverages the existing get_all_settings() method in app/services.py which was already implemented but not exposed via the API. This method queries multiple device settings and handles errors gracefully.

How It Works

1. User makes GET request to /api/nl43/{unit_id}/settings
2. Router validates device configuration exists and TCP is enabled
3. NL43Client queries device for each setting sequentially (with 1-second delays)
4. Individual errors are caught and returned as error strings
5. Response returned with all settings in JSON format

Usage Example

# Quick verification before measurement
curl http://localhost:8100/api/nl43/NL43-001/settings

# Response:
{
  "status": "ok",
  "unit_id": "NL43-001",
  "settings": {
    "measurement_state": "Stop",
    "frequency_weighting": "A",
    "time_weighting": "F",
    "measurement_time": "00:01:00",
    "leq_interval": "1s",
    "lp_interval": "125ms",
    "index_number": "0",
    "battery_level": "100%",
    "clock": "2025/12/24,20:45:30",
    "sleep_mode": "Off",
    "ftp_status": "On"
  }
}

Benefits

1. Single request - Get all settings at once instead of multiple API calls
2. Pre-flight checks - Verify configuration before starting measurements
3. Documentation - Easy to save configuration snapshots for audit trails
4. Troubleshooting - Quickly identify misconfigured settings
5. Multi-device - Compare settings across multiple devices

Performance Notes

• Query time: ~10-15 seconds (due to required 1-second delays between commands)
• Rate limiting: Automatically enforced by NL43Client
• Error handling: Partial failures don't prevent other settings from being retrieved
• Caching recommended: Settings don't change frequently, cache for 5-10 minutes

Testing

To test the new endpoint:

1. Start the server:

   uvicorn app.main:app --reload --port 8100
   

2. Configure a device (if not already configured):

   curl -X PUT http://localhost:8100/api/nl43/test-meter/config \
     -H "Content-Type: application/json" \
     -d '{"host": "192.168.1.100", "tcp_port": 80, "tcp_enabled": true}'
   

3. Query settings:

   curl http://localhost:8100/api/nl43/test-meter/settings
   

4. Check Swagger UI:

   • Navigate to http://localhost:8100/docs
   • Find "GET /api/nl43/{unit_id}/settings" endpoint
   • Click "Try it out" and test interactively

Integration Tips

Frontend Integration

// React/Vue/Angular example
async function verifyDeviceBeforeMeasurement(unitId) {
  const response = await fetch(`/api/nl43/${unitId}/settings`);
  const { settings } = await response.json();

  // Verify critical settings
  if (settings.frequency_weighting !== 'A') {
    alert('Warning: Frequency weighting not set to A');
  }

  // Check battery
  const batteryPercent = parseInt(settings.battery_level);
  if (batteryPercent < 20) {
    alert('Low battery! Please charge device.');
  }

  return settings;
}

Python Automation

def ensure_correct_config(unit_id: str, required_config: dict):
    """Verify device matches required configuration."""
    settings = get_device_settings(unit_id)

    mismatches = []
    for key, expected in required_config.items():
        actual = settings.get(key)
        if actual != expected:
            mismatches.append(f"{key}: expected {expected}, got {actual}")

    if mismatches:
        raise ValueError(f"Configuration mismatch: {', '.join(mismatches)}")

    return True

Future Enhancements

Potential improvements for future versions:

1. Filtered queries - Query parameter to select specific settings
2. Diff mode - Compare current settings to expected values
3. Batch queries - Get settings from multiple devices in one request
4. Settings profiles - Save/load common configuration profiles
5. Change detection - Track when settings were last modified

Support

For questions or issues with this feature:

• See SETTINGS_ENDPOINT.md for detailed documentation
• Check README.md for general API usage
• Review COMMUNICATION_GUIDE.md for protocol details

Version Info

• Added: December 24, 2025
• API Version: Compatible with existing v1 API
• Breaking Changes: None - purely additive feature