NMEA question

[tallyHo]

I just purchused a 25CC, and it currently has the radar and a a DSC configured VHF NMEA connected to the autopilot. I have installed a Furono GPS with the intent of using it as the NMEA source. Is anyone familiar with the current configuration? Does it make sense to reconfigure to the GPS?

[Bluefin 32]

The autopilot is getting a GPS signal from some other device so unless you are removing it, you may as well leave well enough alone. Alternatively, if you change the GPS signal input to the autopilot, that would change the VHF input as well. What autopilot and current GPS unit do you have?

[tallyHo]

The GPS that was in the boat was a Garmin 2006, but I don't believe it had the NMEA output connected. It did not have my region chip in it, so I have replaced it with a Furuno GP7000S. That change has been made, so I plan to source the NMEA with it. The autopilot is a Simrad A11. From what I read in the manual, it excluded NMEA input leading me to believe that it is the source. Could it have been used for course information only and not positioning?

[Bluefin 32]

Depending upon which autopilot control box is installed with your Simrad AP11, it will have the capacity to accept NMEA position and navigation data from one or two GPS/plotters. It will also have an input for the electronic compass. The autopilot box also has NMEA outputs that can relay the same data (and heading data from the compass).

You will need at a minimum to connect the one of the NMEA out ports of the Furuno GP7000 to one of the NMEA in ports on the autopilot. You can connect the NMEA in port of the VHF to the same NMEA out port of the GP7000 or leave it on the NMEA out port on the autopilot if it is connected to it now.

I don't think the GP7000 can display DSC position data so there is probably no point in connecting the NMEA out from the VHF. But do not be confused -- you must connect the NMEA output from the GP7000 to the NMEA input of the VHF or you won't have position data transmitted if you use the DSC for a distress call.

[tallyHo]

OK Thanks. It is good to know the autopilot relays data. That was not clear from the manual. I plan to hook the autopilot and DSC VHF to to the one
output port of the GP7000. I also want to connect the radar. Can a single output port drive three devices, or should I use the second output port on the GPS
for the radar?

Thanks for your help

[Bluefin 32]

One port should be able to handle all three devices. But since you have the extra port available, it would be prudent to connect the VHF to its own port since it is a safety item. That way problems with the other equipment would be less likely to prevent the VHF from getting position data in an emergency.

The autopilot will not retransmit 100% of the NMEA data sentences that it receives. Look in the manual (which you can download from the Simrad Yachting website if you don't have one) and it will show you a list. It is most of the important ones you would be likely to need.

[tallyHo]

OK thanks. Your point about the VHF is a good point. I will put it on its own port. I think I have it pretty well mapped out what I need to do. Thanks for your help.