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Connect a Signal K server

Feed a Signal K server, or any Signal K client such as a web instrument panel, with deltas built from the simulated vessel. The message and path layout is on the Signal K reference page.

Serve deltas over WebSocket

Add a WebSocket server output with the signalk encoding. From the command line:

nmeasim run --websocket 3000 --encoding signalk

In the desktop application add a WebSocket server output on the Outputs tab of File → Settings..., set its Encoding to Signal K and its port to 3000. Every client that connects receives the hello message and then one delta per output period (1 s by default; lower it in the output's Period field for smoother instruments).

Check the stream from a terminal with any WebSocket client, or with the check script shipped in the repository:

nmeasim run --stdout --encoding signalk --quiet --duration 3 | python3 tools/check_signalk_stream.py

Feed a Signal K server

The Signal K server reads NMEA 0183 and Signal K deltas from TCP, UDP and serial connections through its Data Connections page.

  1. In the server's admin interface open Server → Data Connections → Add.
  2. Choose Data Type: Signal K, Source: TCP client (or WebSocket), enter the address of the machine running the simulator and the port of the output.

  3. For a TCP source configure a TCP server output with the signalk encoding in the simulator, for example:

    { "type": "tcp-server", "port": 8375, "encoding": "signalk", "period_ms": 500 }

  4. Restart the server. The vessel appears in the Data Browser under the context vessels.urn:mrn:imo:mmsi:239000001, or whatever context the output is set to.

To feed the same server with NMEA 0183 instead, add a plain TCP server output on port 10110 and a Data Type: NMEA 0183 connection; both can run at the same time.

Choose the context

By default the deltas belong to vessels.urn:mrn:imo:mmsi:<MMSI> with the MMSI from the AIS static data of the profile. Set signalk.context on the output (or the Context field in the settings dialog) to another vessel URN, or to an aircraft context such as aircraft.urn:mrn:signalk:uuid:... for a flight simulator feed; the hello message's self follows the same setting.

Send only some paths

The output's sentence filter lists leading path segments for a Signal K output: navigation sends every navigation path, environment.wind, propulsion the wind and the engines.