AIS link up

[jon and michie]

Hi - I am hoping this maybe a straight question.
I have an Icom IC M 423 dsc radio which can link up to an Ais unit - does it have to be of a Icom manufacture or can I use any other make ?
Jon

 

[PaulRainbow]

Hi - I am hoping this maybe a straight question.
I have an Icom IC M 423 dsc radio which can link up to an Ais unit - does it have to be of a Icom manufacture or can I use any other make ?
Jon

What are you trying to achieve ?

 

[jon and michie]

Hi Paul and thank you for your reply - I am thinking of getting an ais unit and under Icom it is listed as an accessory to make dsc calling easier (whether I would is another question) however if I did get a ais unit I think I would like to link up

here is the link to my radio and under the accessories tab is the MA 500 tr ais unit
IC-M423 : Mounted VHF/DSC Marine Radio - Icom UK

Jon

 

[pvb]

Hi - I am hoping this maybe a straight question.
I have an Icom IC M 423 dsc radio which can link up to an Ais unit - does it have to be of a Icom manufacture or can I use any other make ?
Jon

The M423 can be linked to an Icom MA-500TR transceiver so you can transmit DSC calls to AIS targets. It probably won't work with any other transceiver.

 

[jon and michie]

Thanks pvb

 

[prv]

It probably won't work with any other transceiver.

I disagree - I think it probably will. Can't be sure, because Icom don't provide enough information, but the connection is explicitly NMEA0183 and their AIS unit is documented as sending xxDSC sentences to the radio. It would be somewhat perverse for them to design their own proprietary system to duplicate what's been standardised in NMEA0183 for years.

In your place, if I wanted this, I'd probably buy online, test on the bench before expending any effort installing things, and send back under DSRs if it turns out not to work.

Pete

 

[rogerthebodger]

It looks like the Icom MA-500TR transceiver outputs NMEA messages at 4800 and 38400 which are the standard AIS message formats, so you may be able to connect to any other AIS receiver or tranever that has the same message output like the NASA AIS engine.

I have a NASA AIS engine sending the AIS messages to my Standard horizon DSC radio OK.

Check in the manual of your radio for the AIS receive data.

MA-500TR : AIS Products - Icom UK

https://icomuk.co.uk/files/icom/PDF/productManual/IC-M423_1.pdf

section 10 of the manual specifies the connections and specifies NMEA data on the brown and white but is not very forthcoming with regard to the messages and speed of the transmission

 

[PaulRainbow]

Hi Paul and thank you for your reply - I am thinking of getting an ais unit and under Icom it is listed as an accessory to make dsc calling easier (whether I would is another question) however if I did get a ais unit I think I would like to link up

here is the link to my radio and under the accessories tab is the MA 500 tr ais unit
IC-M423 : Mounted VHF/DSC Marine Radio - Icom UK

Jon

It has to be Icom, and it has to be the MA-500TR it won't even work with the newer Icom AIS.

The MA-500TR will only initiate a DSC call with specific Icom VHF sets, the MA-510TR will also only initiate a call to specific VHF sets, those specific sets differ to those compatible with the MA-500TR.

I don't know what other electronics you have onboard, but i'd consider it more important to display AIS on a plotter, rather than the tiny Icom screen. If you could do both, so much the better. It's also worth noting that the MA-500TR only outputs NMEA 0183.

 

[pvb]

I disagree - I think it probably will. Can't be sure, because Icom don't provide enough information, but the connection is explicitly NMEA0183 and their AIS unit is documented as sending xxDSC sentences to the radio. It would be somewhat perverse for them to design their own proprietary system to duplicate what's been standardised in NMEA0183 for years.

In your place, if I wanted this, I'd probably buy online, test on the bench before expending any effort installing things, and send back under DSRs if it turns out not to work.

So it might work? I wouldn't even bother. The MA-500TR is a clunky-looking piece of equipment with a poor screen. Better to put the money into kit which will allow a direct DSC call to an AIS target on a chartplotter screen.

 

[PaulRainbow]

It looks like the Icom MA-500TR transceiver outputs NMEA messages at 4800 and 38400 which are the standard AIS message formats, so you may be able to connect to any other AIS receiver or tranever that has the same message output like the NASA AIS engine.

I have a NASA AIS engine sending the AIS messages to my Standard horizon DSC radio OK.

Check in the manual of your radio for the AIS receive data.

MA-500TR : AIS Products - Icom UK

https://icomuk.co.uk/files/icom/PDF/productManual/IC-M423_1.pdf

I think you're confused Roger, what would be the point of connecting the Icom AIS to a NASA AIS ?

I'm confused too though, what is your NASA AIS sending to the SH VHF ?

 

[PaulRainbow]

I disagree - I think it probably will. Can't be sure, because Icom don't provide enough information, but the connection is explicitly NMEA0183 and their AIS unit is documented as sending xxDSC sentences to the radio. It would be somewhat perverse for them to design their own proprietary system to duplicate what's been standardised in NMEA0183 for years.

In your place, if I wanted this, I'd probably buy online, test on the bench before expending any effort installing things, and send back under DSRs if it turns out not to work.

Pete

What other makes of AIS do you suggest he order to try connecting to his Icom VHF, to be able to initiate a DSC call from the AIS unit ?

 

[prv]

So it might work? I wouldn't even bother. The MA-500TR is a clunky-looking piece of equipment with a poor screen. Better to put the money into kit which will allow a direct DSC call to an AIS target on a chartplotter screen.

That's certainly true - and I think it's rather the point. The OP wants to use other AIS kit, not the MA-500TR, but would like for it to initiate DSC calls on his existing M423. The question he's actually meaning to ask is whether or not the VHF accepts standard DSC setup sentences - its manual doesn't say either way, because Icom would like him to buy their other kit. I don't know either, but I note that the clunky Icom AIS appears to output them, and if it does then that implies that the VHF accepts them.

Pete

 

[prv]

What other makes of AIS do you suggest he order to try connecting to his Icom VHF, to be able to initiate a DSC call from the AIS unit ?

The older Vesper units certainly emitted the relevant sentences; I assume the new ones will if they still have NMEA0183 (I haven't checked). But most people would probably prefer to initiate the call from a plotter rather than a dedicated AIS display, and plotters with NMEA0183 outputs are getting thin on the ground. I believe there are NMEA2000 PGNs for this, so perhaps a particularly capable 2k<->0183 converter is what's needed? Not sure I'd bother, but that doesn't mean the question's invalid.

Pete

 

[rogerthebodger]

MY SH radio will accept( input) the AIS messages from an outside sauce which in my case is a NASA AIS engine.

The OP's radio also has an AIS message input and in the case of the icon comes from the icom AIS device. The specification of your recommended icon AIS is NMEA at 38400 bps so the radio could receive the NMES AIS messages from any device that outputs old AIS NMEA messages at 3840 bpi.

The one advantage is that the icon transponder also sends the OP's boat his position in AIS format but also will allow a DSC message to be dent from the AIS screen.

I have the AIS receive on my plotter but as the SH will not receive an input message to send a DSC call that function is not available for me from my plotter but I can still do the from my radio as I have the AIS data on my radio screen in order of CPA

 

[rogerthebodger]

OpenCPN (the chart plotter I use) inputs all NMEA AIS /GPS messages and I was going to write an add on for OpenCPN to send the DSC message to my radio but as the SH does not accept a DSC message so I never bothered but someone may have .

 

[PaulRainbow]

Roger, you previously said

It looks like the Icom MA-500TR transceiver outputs NMEA messages at 4800 and 38400 which are the standard AIS message formats, so you may be able to connect to any other AIS receiver or tranever that has the same message output like the NASA AIS engine.

I'm at a loss as to why anyone would want to connect two AIS transceivers together ???

MY SH radio will accept( input) the AIS messages from an outside sauce which in my case is a NASA AIS engine.

Which VHF do you have Roger ?

The OP's radio also has an AIS message input and in the case of the icon comes from the icom AIS device. The specification of your recommended icon AIS is NMEA at 38400 bps so the radio could receive the NMES AIS messages from any device that outputs old AIS NMEA messages at 3840 bpi.

What do you think the OP's VHF will do with AIS data, at 38440 or any other baud rate ? It cannot do anything with AIS data, all it will do is to initiate a DSC call to an AIS target that was shown on the Icom AIS screen.

The one advantage is that the icon transponder also sends the OP's boat his position in AIS format but also will allow a DSC message to be dent from the AIS screen.

I have the AIS receive on my plotter but as the SH will not receive an input message to send a DSC call that function is not available for me from my plotter but I can still do the from my radio as I have the AIS data on my radio screen in order of CPA

Yes, this is the only function that connecting the specific Icom VHF to the specific Icom AIS, nothing else.

 

[PaulRainbow]

The older Vesper units certainly emitted the relevant sentences; I assume the new ones will if they still have NMEA0183 (I haven't checked). But most people would probably prefer to initiate the call from a plotter rather than a dedicated AIS display, and plotters with NMEA0183 outputs are getting thin on the ground. I believe there are NMEA2000 PGNs for this, so perhaps a particularly capable 2k<->0183 converter is what's needed? Not sure I'd bother, but that doesn't mean the question's invalid.

Pete

Yes, Vesper AIS units did this a decade ago, not sure if they still do, but it only worked with a very limited number of VHF sets. It's be pointless risking it working with a Vesper unit, when the OP knows it will work with the Icom MA-500TR, IMO.

I'd definitely want to initiate the call from the plotter. My Garmin plotter will initiate such a call, but only to a Garmin VHF. Mine is connected to a Garmin black box VHF/AIS via N2K and the feature works. The only other plotters that i'm aware of that will initiate a DSC call or from B&G/Simrad, but only with B&G/Simrad VHF sets.

I'm not sure, but it looks suspiciously like they might be using custom PGNs to restrict this feature to their own kit.

 

[laika]

The OP's radio also has an AIS message input and in the case of the icon comes from the icom AIS device.

I don't believe it does. Checking the manuals (because with the same thought as you before you posted re: OpenCPN so this had me interested) it seems that the DSC sentences are not transmitted on the same interface as AIS. It's on the one which is used for sharing GPS. Moreover AIS targets can't be selected for individual calls on the radio as they presumably can be on your standard horizon, they need to be selected on on the MA500 which then initiates the call with a DSC sentence to the M423.

I think I'm on the same page as prv with this and the same as you except you may have inferred the method of operation from your radio where the M423 isn't actually doing anything with AIS data (as far as I can see). So my response to the OP is:
It might not need to be ICOM but you'd at least have to have something which (a) had some kind of interface (mine and many AIS units don't have a display) and (b) allows the user to select a target to initiate a DSC individual call to and sends a DSC sentence over NMEA-0183. I doubt there's many that do and you might have more luck finding a plotter which can do it when connected to an AIS unit. As prv suggests, plotters which are new enough to initiate calls to AIS targets but still have NMEA-0183 interfaces might be thin on the ground which brings us to Rogershaw's OpenCPN suggestion (I had the same idea).

Best analysis of DSC sentences I've seen is this:
continuousWave: Whaler: Reference: Data Interface in Digital Selective Calling Class-D Radios

...but it's a little hazy in places and I'm not sure you'd want to be mucking about with DSC without a good idea of what you were doing. Would be excellent if someone who has something which can initiate calls over DSC (ie an MA500 or a plotter which can do it over NMEA-0183) could look at individual call sentences being put out

 

[rogerthebodger]

Roger, you previously said



I'm at a loss as to why anyone would want to connect two AIS transceivers together ???

It looks like the Icom MA-500TR transceiver outputs NMEA messages at 4800 and 38400 which are the standard AIS message formats, so you may be able to connect the Icom Radio to any other AIS receiver or tranever that has the same message output like the NASA AIS engine.

Re reading my post I can see as I did not make it clear. I ment connecting to the OP's the Icon radio

Which VHF do you have Roger ?

I have a SH 2000. This require a AIS input and as I already had a NASA AIS engine feeding my OpenCPN via a USB Rs232 converter I did not need a radio which included an AIS receiver. I already has a RS232 GPS mouse lying around so I used that to feed GP into the radio.

Also I use NavMonPC to combine the incoming messages for OpenCPN and this has a AIS radar type display I did not need a seperate display. The NASA AIS engine feeds both the SH radio and the OpenCPN. I Also have a USB GPS muse for OpenCPN. My PC which runs OpenCPN has a screen both in the cockpit and at the nav station where the main SH radio is located and a RAM in the cockpit.

What do you think the OP's VHF will do with AIS data, at 38440 or any other baud rate ? It cannot do anything with AIS data, all it will do is to initiate a DSC call to an AIS target that was shown on the Icom AIS screen.

If the OP needs that funcilaibility thn fine but I personally don't think its too important as the radio has that function anyway. Also the Icon unit is a AIS transmitter as well as a receiver. Again dies the OP want that function. To me the AIS receive and display is more important considering the extra cost of an AIS transceiver

The Icom AIS radar outputs AIS data in NMEA format at 38440 so the OP's Icom radio must be able to receive the AIS data at that speed. So it must be able to receive AIS data from any other device that output AIS data at 38440.

Yes, this is the only function that connecting the specific Icom VHF to the specific Icom AIS, nothing else.

 

[rogerthebodger]

(QUOTE=""]
Rogershaw said:
The OP's radio also has an AIS message input and in the case of the icon comes from the icom AIS device.
[/QUOTE]

I don't believe it does. Checking the manuals (because with the same thought as you before you posted re: OpenCPN so this had me interested) it seems that the DSC sentences are not transmitted on the same interface as AIS. It's on the one which is used for sharing GPS. Moreover AIS targets can't be selected for individual calls on the radio as they presumably can be on your standard horizon, they need to be selected on on the MA500 which then initiates the call with a DSC sentence to the M423.

I think I'm on the same page as prv with this and the same as you except you may have inferred the method of operation from your radio where the M423 isn't actually doing anything with AIS data (as far as I can see). So my response to the OP is:
It might not need to be ICOM but you'd at least have to have something which (a) had some kind of interface (mine and many AIS units don't have a display) and (b) allows the user to select a target to initiate a DSC individual call to and sends a DSC sentence over NMEA-0183. I doubt there's many that do and you might have more luck finding a plotter which can do it when connected to an AIS unit. As prv suggests, plotters which are new enough to initiate calls to AIS targets but still have NMEA-0183 interfaces might be thin on the ground which brings us to Rogershaw's OpenCPN suggestion (I had the same idea).

The Icon AIS radar outputs AIS messages so when connected to the OP's Icom Radio and the Icon AIS manual confirms it outputs NMEA @ 38440. so the Icon Radio must receive the AIS messages @ 38440.

The DSC input NMEA message is @ 4800 so will be on a different input connection which it is.

I could be quite easy to write an add on to OpenCPN to send a DSC message out on a seperate RS232 or USB/RS232 to the separate input to the Icon radio. I considered this but my old SH does not accept the DSC input message so no point for me. I don't see it as that important as I do have a RAM in the cockpit.

The question is "does you radio accept a DSC message that will cause it to make a DSC call without any manual input to the radio. If it can than an add on to OpenCPN can be written to do that function by selecting a target and initiating a call from the OpenCPN screen