head scratching AIS/Plotter/VHF connections

[gjgm]

The easy bit...
Antenna to splitter;splitter to vhf and to AIS; AIS nmea 2k to plotter.
The AIS and plotter also have nmea 0183 and the VHF is only 0183.

The VHF needs the gps data, so I guess that could come from either the plotter over 0183, or the AIS over 0183.
What are the "Talker" outputs for, from the VHF ? What is it sending and to where?

I think on the 0183 cable from plotter I have 20 wires; the 0183 from AIS has 10, and 0183 from VHF has 4, so I think I cannect anything you like! I think I can make a sort of dummy 0183 backbone via the plotter, but am I making unnecessary connections?
Is there anything needed from AIS to VHF (over 0183) and anything needed over 0183 between vhf and plotter (other than gps) ?
Garmin 5000,Vesper Marine xb8000 and Icom 423 (at least, I don't think it is the 423g...)
Nmea 2k vhf would have been handy !

 

[Stats007]

In NMEA 0183 you define a talker and a listener as it's a point to point network unlike NMEA 2000. A talker 'sends' a listener 'receives'.

 

[gjgm]

In NMEA 0183 you define a talker and a listener as it's a point to point network unlike NMEA 2000. A talker 'sends' a listener 'receives'.

Yes, thanks. So on the VHF it needs to listen to the GPS, but what would a VHF/DSC send and to where?

 

[Stats007]

A VHF could forward a gps signal or a distress call though usually you don't bother and it remains unconnected. It depends how you want to connect your equipment. In theory the GPS antennae could connect to the VHF and you could forward it to a chartplotter for example - however since a lot of chartplotters have built-in GPS you forward that signal to your VHF. All depends on what other equipment you have.

 

[rogerthebodger]

Yes, thanks. So on the VHF it needs to listen to the GPS, but what would a VHF/DSC send and to where?

The VHF DSC can receive emergency position data from another DSC VHF. It can also receive non emergency position info. The output from the VHF for these messages can be sent to a plotter to display on the screen. My DSC VHF is connected to a PC punning OpenCPN and I can send position info from my HH DSC VHF to my wife on my main boat and she can see where I am.

There is also a position request that you can send to another DSC VHF and the reply can also be displayed on your plotter.

 

[gjgm]

Thanks.
So makes sense to,from plotter and maybe the ais output,input on 0183 is not needed as the ais info is only needed on the plotter and that will be via n2k?
No need for ais 0183 to,from vhf?

 

[superheat6k]

You need to review how many channels each device has.

AIS generally talks at 38400 so the plotter needs to receive this and be set to this rate. If it has only one channel it will talk at the speed too on its output (NMEA0183).

The VHF DSC will want to talk at 4800 baud in and out. So you need one device to talk to the VHF at low speed. If your Garmin has two channels you can set it all up just fine - one channel at low and one at high speed.

I have never bothered setting up the DSC from the VHF. The idea is that some one sending out a Mayday will have their position displayed on your plotter. I prefer at this point to listen and see for myself where they are, as I think the system (and my brain which has to decipher it all, whilst still navigating) is hitting information overload.

This is especially the case for budget boaters without hyper integrated comms systems for every device under the Sun, that rarely leave the Solent.

 

[gjgm]

You need to review how many channels each device has.

AIS generally talks at 38400 so the plotter needs to receive this and be set to this rate. If it has only one channel it will talk at the speed too on its output (NMEA0183).

The VHF DSC will want to talk at 4800 baud in and out. So you need one device to talk to the VHF at low speed. If your Garmin has two channels you can set it all up just fine - one channel at low and one at high speed.

I have never bothered setting up the DSC from the VHF. The idea is that some one sending out a Mayday will have their position displayed on your plotter. I prefer at this point to listen and see for myself where they are, as I think the system (and my brain which has to decipher it all, whilst still navigating) is hitting information overload.

This is especially the case for budget boaters without hyper integrated comms systems for every device under the Sun, that rarely leave the Solent.

Ok, so the AIS/plotter is over N2k, so I assume they can/will connect at the right speed, or I set it on the plotter.
Then I need 0183 to (and maybe to/from) plotter/vhf, and the rest are surplus to my set up?
Thanks all.