boatmike
Well-known member
As a mechanical engineer, electrics generally I can get my head around but electronics does my 'ed in.
I am upgrading an old chartplotter. The connections on my old one confused me a bit but as it worked I suppose its OK....
Questions are
1 The NMEA common ground on the old one has been connected directly to the same terminal that carries the black power ground wire. Is this OK or should it be isolated from the general boat ground? Also in terms of terminology I am assuming that data IN and data OUT are self explanatory and data comes OUT of an AIS receiver to a port IN at the chartplotter but why are there plus and minus Input and Output wires when there is a common ground ? My chartplotter wiring diagram suggests that the AIS has a single input data wire from the AIS to chartplotter and a common ground and that the boat ground is separate. The old one seems to have the green and black ground wires to a common terminal and a Port Out + from the AIS to a Port In + at the chartplotter AND a Port out - at the chartplotter to a port in - at the AIS. I may be confusing the Outs an Ins and the + an - though. Can some kind soul with a brain please tell me that this is actually more simple than I thunk is wos and tell me how the electronic knitting should be connected please? I am sure its not rocket science when you know how these things work but there does not appear to be a common colour code from one manufacturer to another and my brain 'urts.........
I am upgrading an old chartplotter. The connections on my old one confused me a bit but as it worked I suppose its OK....
Questions are
1 The NMEA common ground on the old one has been connected directly to the same terminal that carries the black power ground wire. Is this OK or should it be isolated from the general boat ground? Also in terms of terminology I am assuming that data IN and data OUT are self explanatory and data comes OUT of an AIS receiver to a port IN at the chartplotter but why are there plus and minus Input and Output wires when there is a common ground ? My chartplotter wiring diagram suggests that the AIS has a single input data wire from the AIS to chartplotter and a common ground and that the boat ground is separate. The old one seems to have the green and black ground wires to a common terminal and a Port Out + from the AIS to a Port In + at the chartplotter AND a Port out - at the chartplotter to a port in - at the AIS. I may be confusing the Outs an Ins and the + an - though. Can some kind soul with a brain please tell me that this is actually more simple than I thunk is wos and tell me how the electronic knitting should be connected please? I am sure its not rocket science when you know how these things work but there does not appear to be a common colour code from one manufacturer to another and my brain 'urts.........
