Connecting DSC VHF to GPS

[jbondy]

We've got a Raymarine C80 mounted in a NavPod at the helm. It is connected via SeaTalk to the S1 Wheelpilot computer mounted on a bulkhead below. We're installing a Ray55 DSC VHF at the nav station and would like to connect it to the C80 GPS so that it could transmit location automatically in a distress situation. To do that, we need to get the NMEA signal from the GPS (out) to the VHF (in).

Secondarily, I believe the VHF can display the location of a received distress call on the GPS if we connect the VHF's NMEA out to the GPS' NMEA in.

The S1's trip computer has both itsd NMEA in and out available. I'm thinking that it would be a shorter run from the VHF to the trip computer so my questions revolve around whether it (the computer) will relay the signals between the GPS and the VHF.

It makes sense to me that the GPS is sending location data to the trip computer, and that the trip computer's NMEA output might be able to be used to pass that data to the VHF. It seems less likely that the trip computer will accept the NMEA data from the VHF and relay it to the GPS, and if it does, how the GPS would know what to do with it.

None of this is covered in any of the manuals. I've written Raymarine tech suppport and have yet to hear back, so I thought I'd try here, too. Any insight into this would be appreciated.

TIA

[sailingdog]

I doubt the autopilot will relay GPS information. You're far better off connecting the NMEA in/out from the VHF direct to the GPS.

[velero]

I got the GPS signal from the E120 via their nmea port, the autopilot ony recieves nmea data no data out.

[jbondy]

Originally Posted by sailingdog

I doubt the autopilot will relay GPS information. You're far better off connecting the NMEA in/out from the VHF direct to the GPS.

And it removes a point of failure from what is supposed to be the emergency function. Thanks.

Originally Posted by velero

I got the GPS signal from the E120 via their nmea port, the autopilot ony recieves nmea data no data out.

What I was afraid of. I guess I'll just have to do it right.

[jbondy]

Follow-up: The Autopilot does take the SeaTalk position data and output it via the NMEA output to the VHF. Mission accomplished until I can do the NMEA connection directly to the C80.

Also, Raymarine Tech Support was unresponsive.

[sailingdog]

Which Raymarine GPS antenna do you have??

[jbondy]

RayStar 125 on a pole at the stern.

[sailingdog]

The Raystar 125 can output in either SeaTalk or NMEA 0183. If you have it setup for NMEA 0183, the VHF, autopilot, and chartplotter display could all use the same signal to get the GPS information—since a single talker (the Raystar 125) can support up to four listeners (VHF, CH, AP, +1 spare).

Don't forget to connect the VHF's NMEA output to the Chartplotter's input so that DSC call positions will show up on the chartplotter.