what you are trying to do is designed to have a single device and get and send data from it. But you have 2 devices and you do not need to use SK, you have just to set a serial output connection in OpenCPN.
- Remove all you have done in SK and plugins.
- Use the openplotter-serial app to set alias for both devices.
- Create the SK connection for your AIS/GPS from the same openplotter-serial app. Do not create connection for your second device.
- Go to opencpn and be sure you have enabled the network connection TCP localhost 10110. You do not need more network connections.
- Create a serial output in opencpn using the alias of your second device.
- Remove all you have done in SK and plugins.
- Use the openplotter-serial app to set alias for both devices.
- Create the SK connection for your AIS/GPS from the same openplotter-serial app. Do not create connection for your second device.
- Go to opencpn and be sure you have enabled the network connection TCP localhost 10110. You do not need more network connections.
- Create a serial output in opencpn using the alias of your second device.