DSC NMEA on Raymarine C-80 & VHF w/ DSC out

[hot wire]

The Uniden VHF has a NMEA out. I figure that goes into the C-80 nmea in. But I don't see an in on the C-80 set-up manual EXCEPT the pair I am already using for the Ray GPS is using. Do I piggy back the TWO inputs into the C-80? Anyone have the correct wire colors?

How do you check the operation....? Do I need someone to send a DSC for the VHF to have the C-80 show a symbol?

Man, I could really use some help on this one.....Thanks.

[Draggin' Bait]

The GPS outbound data will need to go into your VHF input data line, so that the radio will obtain position info. It took me awhile to figure out last winter but once done correctly the radio face will display the exact same lat/long as your gps.

Your C-80 is much newer than my Magellan 6500, so I can't display the radio sources on my GPS screen, which it sounds like you are working toward. There are others here that know electronics way better than I do, but I believe that as long as all your toys are talking the same language they can share data lines (as long as ins-and-outs are matched properly).

[hot wire]

Thanks Draggin-

I do indeed get the data on the VHF. The problem is getting the data FROM the vhf to the Ray C-80. That feature would allow any DSC signal reguested or an emergency recieved, to display itself on my C-80 Chart screen with a location represented by a symbol. So, I think we're on the right track. But I still can't get the NMEA connections figured out as the question is stated above......



Tom

[StickFish]

The Installation manual says that the gPS module is connected to the Seatalk cable. The NMEA cable would be for your radio or other devices. Check page 24 of the installation manual for the description of the seatalk cable.

[Draggin' Bait]

I figured your GPS had some features my older one doesn't! The only input my GPS will accept outside of the standard antenna, is a separate DGPS input from the second antenna. Hope you get it all wired in. Lary

[BiteFactory]

You can splice a few external devices (like a VHF radio and an autopilot) to an NMEA out from your GPS/chartplotter. On any NMEA link you can have many listeners but only one talker. I think it is up to 3, I'll check the NMEA install standards if anyone needs me to.

You need to have NMEA out from the VHF connected to an NMEA input on the chartplotter (not a raymarine guy, just assuming it has NMEA in/out from chartplotter). You will only be able to use that chartplotter NMEA input for the VHF. Only one NMEA talker remember, in this case the VHF is the talker.

My old setup (using a garmin 276 gps) used serial port #1 from the GPS to output NMEA position to the ICOM-402s. I use the input line on gps serial port #1 to accept the VHF messages.

VHF out -> GPS NMEA in
VHF in <- GPS NMEA out
VHF gnd -- GPS gnd

[tinfish]

I had same problem as yourself. I needed to connect a GPS, Heading Sensor, and a DSC VHF to my C-120. Unfortunately the Raymarine C-Series displays only have one NMEA input. In order to input more than one NMEA device you will need an NMEA multiplexer. I went with Raymarine's multiplexer, but other brands are available. Works great, problem solved.

http://www.raymarine.com/raymarine/Produ...product_id=3113

I hope this is helpful to you.

Tin Fish

Make a "data buss" and hook them together.

[garyk]

What Keta said

A $15 Blue Sea data bus bar from WestMarine eliminated the confusion I had of trying to link five different units (TR1, GPS, VHF/dsc, 2 FF'ers).

[tinfish]

Utilizing a buss bar to connect a single NMEA talker to many listeners is certainly valid. However, connecting many talkers to a single listener is not. Data collisions will occur. As I understood his question, he is trying to connect two NMEA talkers (GPS and VHF DSC out) to a single listener (C-80). If this is the case then a multiplexer is required. If I misunderstood the question then I stand corrected.

http://www.shipmodul.com/en/multiplexer.html

Tin Fish

I run an auto pilot, a DSC enabled VHF and my GPS all off of the buss and have no problems. I also use the buss for data -. The comunication is one way, either NEMA out or NEMA in and causes no problems.

[BiteFactory]

Sounds like Keta's system has one talker (the gps) and two listeners (autopilot and vhf).

Now, do you have the vhf talker (output from the vhf) connected to this same common signal line? If so you'd have to connect the gps's input to the common signal line as well. Now the GPS has it's out and in connected to the same signal line.

If so you might be getting away with it because the vhf talker communicates very infrequently. When it does communicate you may get lucky if the incoming DSC message gets through to the gps in-between GPS position messages. I'd have to look at how often the position is transmitted, but let's guess it is once a second. That leaves a lot of empty space for getting lucky on the message getting across. You may miss position reports or distress calls from other boats.

It would be better if the gps input and vhf output were just connected together. Nothing else on the common bus benefits from the incoming DSC messages.

After writing this I realized that it isn't quite that simple. If you just hook up your gps and tell it to output NMEA on port 1 it will be writing out a few other types of messages as well (like miles to waypoint, SOG, ..). Eats into that "lucky" space. If you add a heading sensor sometime for radar, the KVH sensor writes messages 10 times a second.

[BiteFactory]

Here's a BlueSea terminal block bar that allows you to hook up individual lines cleanly.

http://www.bluesea.com/product.asp?P...1=7465&l2=

You can bridge neighboring lines together to share common messages (like one talker / many listeners).

This is different than using a common bus bar, like what you'd use as a ground:
http://www.bluesea.com/product.asp?P...1=7465&l2=

I don't have a common buss. It has individual terminals and jumpers. Everything works on 2 way communication.
The NEMA out from the GPS is hooked to the NEMA in on the VHF and auto pilot, the NEMA out on the GPS is hooked to the NEMA in on the VHF and Auto pilot.

[hot wire]

0

[StickFish]

Go with C since that is what the installation manual says