Connecting AIS via NMEA to Chart Plotter

[castaway]

Further to my enquiry (and thanks for the many well informed replies) about Nasa AIS, can anyone tell me if connecting an AIS engine into my Raymarine C70 plotter via NMEA is a straight forward proceedure ?

All the electrics on my 'new to me' boat are rather perfectly instaled and having not yet even sailed the boat let alone fired up the elecrics in anger I'm reluctant to start sniping into cables.

I could have the yard electrician look at it, but if possible I would prefer to install it myself.

Thanks Nick

 

[alan]

NMEA to C70

Castaway,
Yes, it is a straight forward procedure but the single NMEA port on the C70 will need to be set to the bit (baud) rate for the AIS: 38.4 Kb/s.
Thus the transmit bit rate of the C70 NMEA port will also be 38.4 Kb/s; so if you are using the NMEA port output for other instruments (e.g. GPS to radio) then they likely will not work.

The most "common" way for using the C70 is to use the NMEA port for AIS (set to 38.4Kb/s) and to use the Seatalk for inputting GPS information and also the Seatalk for connecting to other (Raymarine) instruments; or if you need NMEA for oither instruments then Raymarine make a Seatalk to NMEA converter (at a cost!!).

If you want to use the NMEA input port to get GPS information as well as AIS then you will need to multiplex the inputs in some way (e.g. external multiplexer or chose an AIS that also has an NMEA input for GPS). It depends a lot on your overall system set-up.

Hope that helps?

Alan.

 

[Elessar]

Castaway,
Yes, it is a straight forward procedure but the single NMEA port on the C70 will need to be set to the bit (baud) rate for the AIS: 38.4 Kb/s.
Thus the transmit bit rate of the C70 NMEA port will also be 38.4 Kb/s; so if you are using the NMEA port output for other instruments (e.g. GPS to radio) then they likely will not work.

The most "common" way for using the C70 is to use the NMEA port for AIS (set to 38.4Kb/s) and to use the Seatalk for inputting GPS information and also the Seatalk for connecting to other (Raymarine) instruments; or if you need NMEA for oither instruments then Raymarine make a Seatalk to NMEA converter (at a cost!!).

If you want to use the NMEA input port to get GPS information as well as AIS then you will need to multiplex the inputs in some way (e.g. external multiplexer or chose an AIS that also has an NMEA input for GPS). It depends a lot on your overall system set-up.

Hope that helps?

Alan.

All correct but the NASA has a built in mini multiplexer to get over the fact that ray marine only let's you set input and output to the same speed if you're using a nmea gps.

Feed your 4800 baud gps to the ais and in parallel to your dsc radio.

Set your plotter to the ais baud speed (can't remember the speed but it's lots faster than 4800)

The NASA will upgrade the gps speed and feed it onto the plotter. Any other way and you can't get the dsc and the ais to work at the same time without a multiplexor.
The

 

[Elessar]

All correct but the NASA has a built in mini multiplexer to get over the fact that ray marine only let's you set input and output to the same speed if you're using a nmea gps.

Feed your 4800 baud gps to the ais and in parallel to your dsc radio.

Set your plotter to the ais baud speed (can't remember the speed but it's lots faster than 4800)

The NASA will upgrade the gps speed and feed it onto the plotter. Any other way and you can't get the dsc and the ais to work at the same time without a multiplexor.
The

Silly me Alan said the speed 38.4