Raymarine C series/ais/MARPA

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robbieg

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Is anyone running a Raymarine C series inputing AIS data from an AIS engine plus smart heading data from a gyro for the MARPA function? Since the C series only has one NMEA input & the AIS comes in a 38000 baud & the gyro at 4800 baud how do you acheive this? I assume a multiplexer of some sort is require but if anyone can enlighten me it would be appreciated.

Also interest to know what AIS engine is being used-I understand the NASA unit won't work with a muliplexer.
 
Hi Mine Garmin 2110 isnt as complicate as your Raymarine C as far as I know mine only plots the ships on the chart and gives me the details SOG. Heading, COG & MMSI number boat name & destination, But I am still not able to get my AIS engine to chat to the plotter. there are wires for more than one PORT and in the settings Menue you have Port 1 Port 2 so you wire acordingly I have set Port 1 for fast NMEA in & out for AIS and port 2 for other NMEA. Do you know if NMEA 0183 is compable with NMEA 2000. what is MARPA
REgards Mike
 
Because the AIS data and the heading data are coming in at different baud rates, you need a suitable multiplexer. A multiplexer simply 'adds' the data together then sends it (as one 'string') to your equipment. These are available from most of the good electronics suppliers around. A recommended multiplexer is the NDC-2 made by Actisense. This company do them - www.btmarine-electronics.co.uk

MARPA (mini automatic radar plotting aid) comes from commercial tracking systems known as ARPA or ATA. On your radar you can display the speed, heading etc of targets on the screen, however it's only as good as your heading source eg, a good compass or gyro. input.
 
Dont know where or which forum but someone has said that Raymarine are about to launch a multiplexer/ariel splitter (use existing VHF ariel)and AIS engine in one. No doubt it will be expensive but it is likely to simplify the setup. I have the same problem and will wait and see probably give Raymarine a call in acouple of weeks.
 
I have a C80 and Garmin GPSMAP(sending 4800 baud).I'mfitting a NASA AIS which will accept the 4800baud and the aerial(via a splitter)
The AIS will send NMEA to the C80 at 38400 baud. I am buying a flash card to update the C80 from the Raymarine website so that it can be programmed to accept 38400 baud. Fingers crossed.
 
If the gyro is Raymarine then I would have thought it talks Seatalk not NMEA, in which case it just connects into the Seatalk network and you just leave the NMEA-in on the C-series for AIS and the gyro-stabilised heading will come in via Seatalk. If the gyro talks NMEA then just get a Raymarine NMEA/Seatalk bridge (cheaper than many 3rd party NMEA multiplexers), connect the gyro through this to the Seatalk network. If you have (or are going to get) a Raymarine autopilot, then connect the gyro to this.

I have an E-series and have connected a NASA Marine AIS engine to this with no problems. I have a Raymarine "G" autopilot so my heading data is already accurate enough for MARPA.

Keep an eye on eBay, I got the NMEA/Seatalk bridge from there, or look at www.raydirect.co.uk for reasonable prices for all Raymarine kit.

Cheers, Jerry
 
I fitted Raymarine C (C70) series plus high speed giro compas and marpa, last year, with the display on the steering binacle, and have been very impressed. This season I hope to set up AIS to run in conjunction with lap top chart plotting, which will be based at the chart table. I figure AIS will be of more use "downstairs", where the comms are available, and using the two independent systems will provide some measure of overlap protection should one fail.
 
I have this exact configuration but as you point out, there is an issue over baud rates.

Raymarine feed the compass into the C series via nmea at 4800. By doing this they can update the heading information at 10-20hz. Heading info sent via Seatalk is only sent at 2Hz. This slow update via Seatalk will affect MARPA which relies on accurate heading info.

At the time that I fitted my NASA AIS engine I was not able to source a multiplexer in time so I disconnected the Gyro NMEA input to the C80 and to be quite honest I did not notice a difference in MARPA accuracy.

I'm sure that in a heavy seaway where your heading is constantly changing then you will start to have issues but my in my view, under those conditions I would not rely solely on MARPA anyway.

BTW, I discussed this with Raymarine and while they obviously caveated all guidance, they agreed that this should not be a problem.

At some stage I will install a multiplexer but I am not rushing to do that.

Somewhere I have a document that I put together on how to get all the bits talking to each other so let me know if you want it.

Cheers

Wayne
 
Seatalk is not fast enough for high speed heading input (at least 10 readings/second) required for radar stabilisation, thus NMEA has to be used.
 
Very easy to fit...

It's very easy to fit the Raymarine Smart Heading Sensor system, although you need to be careful to choose the best position for the fluxgate compass. Once fitted, the C-series can calibrate it automatically. I fitted mine myself in a few hours (much of that time was spent running wiring in concealed places). The kit is about £500.
 
Re: Very easy to fit...

Thanks for the info its definately a DIY jobbie then.

Out of interest did you notice how stable the targets were in rough water thanks to the fast heading system?
 
Re: Very easy to fit...

The higher quality heading info does give better MARPA performance, although I wouldn't say it's massively improved. Difficult to make a value judgement really. Think it also helps stabilise the radar image generally - quite useful as I usually use radar overlay on a North-up chart.
 
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