How should shielding be grounded on an NMEA 0183 data line?

The correct grounding method for shielding on an NMEA 0183 data line is to terminate to ground at the talker and leave it unterminated at the listener. This approach helps to prevent ground loops, which can introduce noise and disrupt communication between devices. By grounding the shield at the talker, you create a single point of reference for the signal, which helps maintain integrity in the data being transmitted.

When the listener side leaves the shield unterminated, it prevents the shield from creating a return path for currents that could interfere with the received signal. This setup allows the data line to maintain a consistent and clean signal without the risk of interference caused by multiple grounding points. The result is a more reliable communication link between the devices involved in the NMEA 0183 network.