Best way to integrate AIS

[jackh]

Another nmea / seatalk post, for which i humbly apologise, but i've yet to find a convincing answer in manuals or other posts thus far...

AIS will be coming aboard in the near future, and with cheap units for £200 available I'd really like to avoid paying a premium for the RM AIS250 unit.

So my question is this: I have a C70 plotter, S1 wheelpilot and DSC radio. Currently GPS info comes in on seatalk to the C70, where it is forwarded to the radio on nmea. That's been great up till now, but if I introduce AIS then this will occupy the plotter's only nmea port, which leaves my radio void of any position info.

Now, i could shell out £600 on the RM AIS unit, which though expensive, does have multiplexing functionality built in and so could talk to and get position info from the C70 and forward position to the radio. (I hope this much at least is correct)
This setup would be my preference against a system with a dedicated multiplexer but I had another plan and I'm hoping some bright spark can tell me if it'll work.

My autopilot receives position info over seatalk, and the course computer has nmea in/out connections. Is seatalk information forwarded out to these nmea ports - in which case can I just wire up my radio into the computer?

hope that all makes sense, my head hurts just writing it down...

As an aside, if anyone has any thoughts or opinions on the raymarine AIS versus cheaper units (are there performance advantages outside of multiplexing ability? or plotter compatibility differences?) i'd be interested to hear them.

Thanks all

 

[pvb]

Theoretically, you're right, you should be able to get GPS position output (GLL) from the NMEA out port of the course computer. It would be easy enough to try this and confirm that it works before you make a decision on AIS equipment.

The Raymarine AIS250 is expensive, but it does include a multiplexer and an antenna splitter, so I guess they go some way towards justifying its price.

 

[jfkal]

You need to test this. I had a rude awaking when I found out that my 4000 course computer kept the info to itself and did not repeat it out on Seatalk. The RM NMEA-ST interface box does the trick well however. Also beware that AIS sends at a different port speed than "normal" NMEA. So you need a multiplexer which supports that. Or you spend another port for your PC. Not so good because if all that Microsoft stuff on the PC packs up you loose that control also. Better to get a multiplexer box or the RM thingy which is bloody expensive /forums/images/graemlins/frown.gif

 

[boatmike]

Not helpful I know but it's this sort of crap that stops me buying Raymarine. All Standard Horizon stuff works on NMEA and interfaces with anything. It's also much cheaper and I prefer C-Map Max anyway. However I can tell you that my advice was to buy EASY AIS which is very good quality and more sensitive than most. I have not used it in anger yet but it has already located ships in the Solent from my mooring in Fareham creek which I thought would be impossible as theoretically I don't have VHF line of sight. If you can get your interfacing sorted it's good kit and seems to be built well.

 

[WindFinder]

[ QUOTE ]
All Standard Horizon stuff works on NMEA and interfaces with anything.

[/ QUOTE ]

Can someone clarify this for me.

I understand AIS runs on a different baud rate to other NMEA083 devices. Because the C-Series only has one NMEA083 port it can't run AIS and other devices with a different baud rate on the same network.

However the only solutions would seem to be to have the baud rate of every device configurable or provide a second NMEA083 port. Is that what other SH do or is there another cunning way round the problem?


Isn't the obvious solution to the OPs problem to buy AIS kit that talks NMEA2000?

 

[boatmike]

Yes. SH (at least my 500) has 2 NMEA input ports. All you do is go into the menu and configure the ports. Job done.

 

[jackh]

Thanks for those replies - I'll go down with some wires later on and see what talks. It wouldn't surprise me if the computer refused to share information like the 4000 - but that's all part of the fun of interfacing, right?

If i end up needing a multiplexer, it'll probably be the RM AIS, but otherwise i'll definately give the EasyAIS a looksee.

Cheers

 

[DavidMcMullan]

Are you trying to display the AIS info on the C70 plotter?
I have an RL70CRC unit and wasn't aware you could input AIS into it. Is this true?
David.

EDIT - just realised the C70 is different from the RL70. Therefore please ignore comment.

 

[pvb]

[ QUOTE ]
If i end up needing a multiplexer, it'll probably be the RM AIS, but otherwise i'll definately give the EasyAIS a looksee.

[/ QUOTE ]If you need a multiplexer, take a look also at the MiniPlex-AIS which is designed specifically for C/E series displays. £159 inc UK delivery from JG Technologies.

 

[DipperToo]

I am trying to install AIS next Friday. Interestingly, the tech guys at EasyAIS Germany) state that the unit has a built-in multiplexor (single channel input). They claim that if I take the NMEA fast heading output from the raymarine course computer into the EasyAIS box, it will then be multiplexed onto the output data stream. Setting the C80 to the fast baud rate for AIS should still allow the fast heading data to be decoded by the C80.

If this works, a couple of hundred pounds saved. ( I already have a Seatalk/NMEA bridge to manage the VHF radio to for its position signal).

All the UK distributors say you need a separate multiplexor...

Stewart

 

[pvb]

[ QUOTE ]
Interestingly, the tech guys at EasyAIS Germany) state that the unit has a built-in multiplexor (single channel input).

[/ QUOTE ]It does - designed originally for feeding GPS position data, but there's no reason why it shouldn't work with other NMEA data.

 

[PembrokeshirePromise]

Yes - I think you should be OK - I do somthing similar with the C80, AIS and S1 wheelpilot.

The only possible difference is that I'm feeding additioal NMEA data in from a tacktick system - but thinking about it that gets its position from the Raymarine GPS at the moment anyway as does DSC VHF - so this info is initially on SeaTalk to S1 controller - and then gets rebroadcats on NMEA (to DSC, Tacktick, PC etc)

I did ask Raymarine - and they said I'd need a multiplexer - but wasn't sure that the bloke really understood whta I was asking !

Good luck !

 

[PembrokeshirePromise]

Yes you can (well certainly C80 which is just bigger screen)
You may need to update firmware from Raymarine site if you haven't for a year or too.

I've had it for a year now - and think that the abilty to combine - or not - radar/AIS/chart is quite powerful

Second comment on EasyAIS - nicely made

 

[boatmike]

I did ask Raymarine - and they said I'd need a multiplexer - but wasn't sure that the bloke really understood whta I was asking !

Now theres a surprise! /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif

 

[jackh]

Well I've just been down the boat and with the autopilot computer on the seatalk network, position info can indeed be sent on to the radio on nmea. Huzzah!

 

[pvb]

That's good! Now for AIS...

 

[jackh]

Am i right in thinking that the AIS features (guard zones / display only dangerous targets option etc) are determined by my C70, and that all the features I've read about in the AIS250 manual will be available whatever black box receiver i connect?

 

[pvb]

Yes, but buy a decent AIS receiver.

 

[jackh]

Well after the recommendations it'll probably be Easy AIS.

Thanks for the advice, all

 

[Ballistix]

I installed the Digital Yatchs AIS 250. It's a true transponder and interfaces to my Garmin 525S. It's easy on that plotter because it has to NMEA ins and outs. Simply connect your Radio to one port and the AIS to the other. Because the AIS (as most do) uses the high speed interface for NMEA you will not be able to double up or "share" the output to the radio and the AIS, you need two channels.

T