DLMS/COSEM Library for Dart #

A robust, pure Dart implementation of the DLMS/COSEM protocol (IEC 62056), designed for reading smart meters (electricity, water, gas) and other IoT devices.

This library supports both TCP/IP and HDLC (Serial/Optical) transport layers, High-Level Security (HLS) foundations, and provides a strongly-typed API for common COSEM objects.

Features #

• Transport Layers:
  • TCP/IP (IPv4/IPv6)
  • HDLC (Serial, Optical Probe) with SNRM/UA handshake and CRC-16.
• Protocol Support:
  • GET: Read attributes (Normal and Block Transfer for large data).
  • SET: Write attributes.
  • ACTION: Invoke methods (e.g., disconnect relay, capture profile).
  • Selective Access: Read specific ranges (e.g., date-based) from Load Profiles.
• Security:
  • Low Level Security (LLS - Password).
  • High Level Security (HLS) support (Challenge/Response mechanisms).
• Interface Classes:
  • CosemClock (Class 8) - DateTime management.
  • CosemRegister (Class 3) - Energy/Water values with scaler/units.
  • CosemProfileGeneric (Class 7) - Load profiles and event logs.
  • Extensible CosemObject base.
• Encoding: Highly optimized A-XDR (Xml Encoding Rules) reader/writer.

Getting Started #

Add the dependency to your pubspec.yaml:

dependencies:
  dlms: ^1.0.0

Usage #

1. Connecting via TCP #

import 'package:dlms/dlms.dart';

void main() async {
  // 1. Create Transport (TCP)
  final transport = TcpTransport('192.168.1.100', 4059);
  
  // 2. Create Client
  final client = DlmsClient(transport);
  
  try {
    // 3. Connect (LLS Password optional)
    await client.connect(password: '123456');
    print('Connected!');

    // 4. Read Active Energy (Register Class)
    // 1.0.1.8.0.255 = Active Energy Import (+A)
    final obis = ObisCode(1, 0, 1, 8, 0, 255);
    final register = CosemRegister(client, obis);
    
    print('Energy: ${await register.value} Wh');
    
  } finally {
    await client.disconnect();
  }
}

2. Reading Load Profile (Block Transfer & Selective Access) #

The library automatically handles multi-block transfers for large files.

// Define the range (e.g., last 24 hours)
final range = RangeDescriptor(
  restrictedObject: const DlmsValue([], 2), // Columns definition
  fromValue: const DlmsValue('2023-01-01', 10), // Start Time
  toValue: const DlmsValue('2023-01-02', 10),   // End Time
  selectedValues: <DlmsValue>[], // All columns
);

final profile = CosemProfileGeneric(client, ObisCode(1, 0, 99, 1, 0, 255));

// Fetch buffer
final rows = await profile.getBuffer(range: range);

for (final row in rows) {
  print(row); // [DateTime, Energy, Voltage, ...]
}

3. Using HDLC (Serial) #

To use HDLC, you need a stream of bytes (e.g., from flutter_libserialport or dart_serial_port).

// Hypothetical serial port stream
final serialStream = port.inputStream; 
final serialSink = port.write;

final transport = HdlcTransport(
  byteStream: serialStream,
  byteSink: serialSink,
  clientAddress: 0x21, // Public Client
  serverAddress: 0x03, // Logical Device Address (last 2 digits of Serial?)
);

```dart
final client = DlmsClient(transport);
await client.connect();

4. Controlling Disconnect Breaker (Class 70) #

Safely manage the supply remotely.

final breaker = CosemDisconnectControl(
  client, 
  ObisCode(0, 0, 96, 3, 10, 255)
);

if (await breaker.outputState) {
  print('Breaker is CLOSED (Power ON). Disconnecting...');
  await breaker.remoteDisconnect();
} else {
  print('Breaker is OPEN (Power OFF). Reconnecting...');
  await breaker.remoteReconnect();
}

Supported PDU Types #

• AARQ / AARE (Association Request/Response)
• GetRequest / GetResponse (Normal, Next, WithBlock)
• SetRequest / SetResponse
• ActionRequest / ActionResponse

Contributing #

Contributions are welcome! Please open issues or submit PRs for:

• Additional Interface Classes (e.g., Data, RegisterMonitor).
• HLS Mechanisms (GMAC, SHA256 implementation).
• More robust Transport layers.