I am glad to hear the radar is working as expected.
You can check your NMEA 0183 input data by using the PORT MONITOR button, on the port in question, within the INSTALLATION WIZARD. There is no port reset. If you wire data into the port, you should see the data on the PORT MONITOR. Once you know that the data is received by the system, you should CHECKMARK the type of data under the INPUT section of that port, so the system will process it. For example, if you wire suitable heading data into data 3; you would first check that the data is coming in via the PORT MONITOR. If it is, then you would checkmark "HEADING" box under the input section for that port.