Other examples

Connecting a USB-RS422 converter

You probably still have some devices onboard that use the old NMEA 0183 protocol. Most commercial plotters collect data from all onboard devices and send it through an RS422 output. To connect these devices to OpenPlotter, you need any inexpensive USB-RS422 converter.

Input data

To obtain data from these converters, follow the same steps as for connecting the GPS in the examples of the previous sections of this chapter. Below are the summarized steps.

Enter an alias and select the type of data:

../_images/serial_rs4221.png ../_images/serial_rs4222.png

Create a signal K connection:

../_images/serial_rs4223.png ../_images/serial_rs4224.png ../_images/serial_rs4225.png

Check the Signal K connection has been made:

../_images/serial_rs4226.png

And check OpenCPN to make sure there is a connection to the Signal K server:

../_images/serial10.png

You should now be ready to get NMEA 0183 data from your boat.

Input + output data

Now that you are getting NMEA 0183 data from your boat, you may also want to send some NMEA 0183 data generated in OpenPlotter to your boat. The classic case is to let openplotter control your autopilot. Let’s see how to configure your route in OpenCPN and send data to the autopilot using the same USB-RS422 converter.

You have to create a UDP connection in OpenCPN to send data to Signal K server. Select Network, Protocol: UDP, Address: 0.0.0.0, DataPort: 10119 (or any unused UDP port on your system), User Comment: opencpnOUT, uncheck Receive input on this Port, check Output on this port, transmit only sentences RMB and APB in Output filtering:

../_images/serial_rs4227.png ../_images/serial_rs4228.png

Warning

Allowing only RMB and APB sentences in the output is important to avoid data loops in your system.

Now you have to create a connection in Signal K server to get data from OpenCPN. Login to the Signal K server, go to Server ‣ Connections and click on Add:

../_images/serial_rs4229.png

Set Input Type: NMEA 0183, ID: opencpnOUT, NMEA 0183 Source: UDP, Port: 10119 (or whatever you have set in OpenCPN), Sentence Event: autopilot, Ignored Sentences: RMB,APB and Click Apply:

../_images/serial_rs42210.png ../_images/serial_rs42211.png

Warning

Ignoring sentences RMB and APB is important to avoid data loops in your system.

Finally, you have to edit your device connection to specify what data should be sent to your boat via the USB-RS422 converter. Go to Server ‣ Connections and click on your device connection, in this case rs422:

../_images/serial_rs42212.png

Set Output Events: autopilot, Ignored Sentences: RMB,APB and Click Apply:

../_images/serial_rs42213.png ../_images/serial_rs42214.png

Warning

Ignoring sentences RMB and APB is important to avoid data loops in your system.

Restart Signal K server and you are done:

../_images/serial_rs42215.png ../_images/serial_rs42216.png

Activate a route in OpenCPN and you will start sending data to your autopilot.

../_images/serial_rs42217.png

Connecting a USB-CAN converter

This tutorial is for the Actisense NGT-1, the OpenMarine CAN-USB Stick (discontinued) and the CANable devices.

Input data

To get data from your NMEA 2000 network you have to select the device, enter an alias and select NMEA 2000 in data field. Finally press Apply and the device will be marked blue:

../_images/serial_can1.png ../_images/serial_can2.png

Then go to Connections tab, select the device and click on Add to CAN Bus:

../_images/serial_can3.png

If you are using a CANable device click on MANUAL and go to CAN Bus chapter to learn how to configure this device.

If you are using an Actisense NGT-1 or an OpenMarine CAN-USB Stick (discontinued) device, select the Baud Rate (usually 115200) and click on AUTO.

../_images/serial_can4.png

The device will be marked blue and you are done:

../_images/serial_can5.png

Open the CAN Bus app to confirm that the device has been added to the CAN-USB tab:

../_images/serial_can6.png

And go to Signal K server to confirm that the connection has been made:

../_images/serial_can7.png

Check OpenCPN to make sure there is a connection to the Signal K server and you are getting data from your NMEA 2000 network:

../_images/serial10.png

Input + output data

If you have any sensor in OpenPlotter sending data to the Signal K server, you can use the same USB-CAN converter to send this data to your NMEA 2000 network.

To protect your network, the Actisense NGT-1 and the OpenMarine CAN-USB Stick (discontinued) devices have most PGNs blocked for transmission. On CANable devices, PGNs transmission is not blocked.

To unblock the PGNs you want to send to your NMEA 2000 network, go to CAN Bus app, select the device and click on Open device TX PGNs:

../_images/serial_can8.png

Enable the PGNs you want to unblock and click Apply:

../_images/serial_can9.png

Note

If you see this message: The list of enabled PGNs is empty, you may need to try a different baudrate or reset your device to 115200 bauds, click on CAN-USB Setup to fix your device baud rate.

Click OK to write changes to the device:

../_images/serial_can10.png

Finally, you have to tell the Signal K server what PGNs you need to convert from Signal K format to NMEA 2000 format (for any device model). To do this we use the plugin Signal K to NMEA 2000. Click on SK → NMEA 2000 and you will be directed to the configuration page of this plugin:

../_images/serial_can11.png

Enable Active and the desired PGNs:

../_images/serial_can12.png

Click on Submit at the bottom of the page and you are done:

../_images/serial_can13.png