a. Ensure your software is the latest version. Early versions might not support AIS information. b. Be sure to test your chartplotter and the receiver in an area where AIS signals are present.
a. Make sure there is firm connections for antennas. b. Either channel is receiving data (flashing green signal) c. Might be a bad serial cable. Try another cable.
a. New chartplotters support AIS data. Be sure your chartplotter has the latest firmware update. b. Ensure the baud rate for the inbound NMEA port on the chartpotter is set to 38400 baud. c. Be sure to test your chartplotter and the receiver in an area where AIS signals are present.
Connect the unit to a PC via serial cable and run a terminal emulation package (e.g. Hyperterminal on a Windows-based PC) with correct COM port and 38400 baud rate.