Help with AMEC 101 CYPHO AIS, OpenCPN wiring.

[nixontankgirl]

I have just installed an AIS, wired the GPS to it and plugged it into the USB. I am finding the wiring diagram a little confusing, I had thought it was going to output a GPS signal via the USB but it doesn't.

I am getting data to my laptop from the AIS. I have changed the port settings.

So, what I want to know is;

Does the AIS need the GPS signal? Are the CPA calculations done in the AIS or OpenCPN?
And in the wiring diagram there are 2 wires TXP and TXN that 'transmit AIS and GPS Data'. I presume if I was somehow to connect those to my laptop then the GPS data would be available via OpenCPN. But how do I connect 2 wires to my laptop? I guess I cant just twist them onto a chopped up USB cable as there are no drivers etc.......