amikeren

We have HP-1228 plotter and recently  we buy an AIS HA-102 transponder/receiver. Finally we have all the connectors and plugs etc and we are in the process of connecting the AIS to the plotter, but we have come up with a problem. We need to connect 2 wires to the plotter and we can only identify one of them – the Orange AIS output. See attached image from your user manual below. What is the second color that we need?