What are the connections on the OPTO-4?
The RS232 end is a female 9-pin D-Sub DB9 connector following the standard 9-pin RS232 pin out specification.
The other end has bare wires. An isolated input pair A/+ and B/- for connection to an NMEA Talker, using RS422 voltage levels. A non-isolated output pair A/+ and ground for connection to an isolated listener, using RS232 voltage levels. There is also a shield wire at this end which connects through to the DB9 shield.
For more information on NMEA 0183 and how it works, please download our free guide to NMEA 0183 networking here: https://actisense.com/everything-to-know-about-nmea-0183-guide/