Navbus / NMEA wiring ?!?
OK, so I've got the manuals for my Navman 7200 VHF and my 6600 Trackfish. So far so good. I can connect them using NAVBUS which will give me even more function than NMEA, even better. But wait, the polarity is given in one manual + and - (orange and blue) but not in the other manual. All it says is NAVBUS for both the blue and gray wires. Now, I know NAVBUS is a 2 way without seperate in and out so surely the blues go together and the orange to the gray, but wait, there is a label on the wires, the blue is now + and the gray -. What is going on, has anyone else had any experience in connecting using NAVBUS ?
As for the NMEA, is it common for there to be a ground and + and a seperate + and - for the in and out ? How come the - is not ground for both in and out ? i.e. common - and 2 signal lines.
Anyway I shall find out tomorrow when I power up. I shall post the results.
Hope someone can shed light on this.