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newbie- · 01-06-2021, 23:38

Hey everyone, I'm working on my first AIS instillation and I decided to go with the em-trak A100. It's class A unit which I'd like to use due to the longer range.

Does anyone have the A100 setup as a transceiver?

I'm waiting on mine to come in the mail and reading the manual in advance to get my ducks in a row. Looks like it needs some sensor inputs to be operational.

It requires Speed over Ground (SOG), Course over Ground (COG) and Rate of Turn (ROT) sensors in to a junction box.

The setup is a little more complex than I expected. I don't currently have SOG, COG, or ROT available. So I'm working out what I need for these.

I'd appreciate any advice or your experience on getting the A100 setup. I plan to use it along with OpenCPN.

newbie- · 02-06-2021, 00:06

OK answering my own question. On page 8 of the manual it says:
'The vessel's dynamic data which includes location, speed over ground (SOG) and course over ground (COG) is calculated automatically using the internal GNSS receiver."

So it looks like I don't need any extra sensors. Additional inputs appear to be optional.

tanglewood · 05-06-2021, 15:57

You will also need HDT which is true heading. Without all the above, the device will be in a constant state of alarm. You might be able to ignore it, but I would recommend against it.

Class A and B are opposite each other with respect to internal GPS data and external instrument data.

Class B gets all it's data from it's own GPS, so it can operate even if not interfaced to the rest of the boat instruments.

Class A must be hooked up to the boat's instruments and requires a minimum set of data. I think it's HDT (true heading), ROT (rate of turn), SOG (speed over ground), and COG (course over ground). The internal GPS is for back up only. If you don't have a sat compass, it can be a trick to get HDT to satisfy the AIS.

newbie- · 05-06-2021, 16:50

Quote:

Originally Posted by tanglewood

You will also need HDT which is true heading. Without all the above, the device will be in a constant state of alarm. You might be able to ignore it, but I would recommend against it.

Class A and B are opposite each other with respect to internal GPS data and external instrument data.

Class B gets all it's data from it's own GPS, so it can operate even if not interfaced to the rest of the boat instruments.

Class A must be hooked up to the boat's instruments and requires a minimum set of data. I think it's HDT (true heading), ROT (rate of turn), SOG (speed over ground), and COG (course over ground). The internal GPS is for back up only. If you don't have a sat compass, it can be a trick to get HDT to satisfy the AIS.

Yeah you're right about that. I just got everything together for a test fit today and I'm getting a list of alerts about invalid heading on the A100. The GPS antenna may be having trouble under the metal covered moorage.

But I am picking up AIS signals on the A100 display. I ordered a RS232 to USB cable and I'll try using that to get AIS targets on OpenCPN.

I had another thread about getting sensors in to the A100 junction box. I'm struggling a little on figuring out what sensors make sense to buy and add to the network to satisfy the AIS. A sat compass is about $1000... ouch. I do need heading for radar overlay too. But it's a puzzle to pick all the parts that work well together.

I'm curious how well the internal GPS will do when I'm out from under the roof and under way.

It's been really interesting learning about this stuff. I just got my FCC radio license and callsign on Friday.

tanglewood · 05-06-2021, 19:29

The GPS will never give you heading, only COG. You will need a heading sensor of some sort. There are one or two rate compasses that, if fed variation from an external source, will output HDT. But those rate compasses are generally in the $700 range. The new, smaller sat compasses are no more expensive than the combination of a good rate compass and a good GPS, both of which they include and do better. So I think they are a really good bang for the buck. But still $1000.

Also keep in mind that the alarms won't go away until you feed all the data in from external sources. The data from the built in GPS antenna will not satisfy it, though it's required too. You need both for the alarms to go away. Welcome to the more strict world of IMO certified devices.....

newbie- · 05-06-2021, 20:10

Agreed - it's good value especially with a great gps included. Weighing on that.

Going to try a Furuno PG700 Fluxgate heading sensor tomorrow. Wondering if it will post all the sentences to make the AIS happy. That's a NMEA 2000 device and I'll have to convert the signal to NMEA 0183 for the A100.

https://www.furunousa.com/-/media/si...ons_manual.pdf

Vessel Heading (PGN: 127250)

"PGN: Parameter Group Number. Equivalent to NMEA0183 sentence"
An I reading this right? It's a NMEA 2000 device that sends NMEA 0183 sentences? What..

tanglewood · 06-06-2021, 15:57

Quote:

Originally Posted by newbie-

Agreed - it's good value especially with a great gps included. Weighing on that.

Going to try a Furuno PG700 Fluxgate heading sensor tomorrow. Wondering if it will post all the sentences to make the AIS happy. That's a NMEA 2000 device and I'll have to convert the signal to NMEA 0183 for the A100.

https://www.furunousa.com/-/media/si...ons_manual.pdf

Vessel Heading (PGN: 127250)

"PGN: Parameter Group Number. Equivalent to NMEA0183 sentence"
An I reading this right? It's a NMEA 2000 device that sends NMEA 0183 sentences? What..

If I remember correctly, the PG 700 is one of the few magnetic compasses that can generate the HDT true heading NMEA 0183 sentence. Check the manual for details, but I think you first connect it to N2K, and some other device on N2K needs to be sending the Variation PGN. It will typically come from a compass or chart plotter. Beware if it's the chart plotter because it will only generator the PGN when the plotter is on. A GPS that is always on is a much better choice, but not all GPSs generate Variation.

Then I think with some configuration, the PG-700 will generate HDT on it's 0183 output. It takes the magnetic reading that it senses, applies the Variation adjustment that it's receiving on N2K, and produces HDT.

The other compass I know of that can do the same thing is a Maretron SSC-300 or SSC-200.

newbie- · 06-06-2021, 16:16

I'm probably ordering a sat compass tonight. It's not all that much more than a PG700 and you get a far better device with a lot more useful outputs. And no calibration.

But looking at the back plate of the A100 AIS today... I have an extra port that doesn't match the online manuals. The port is illustrated in the paper manual that came with the unit but I can't find it labeled anywhere.

Anyone else think that black 5 pin port looks suspiciously like a NMEA 2000?

ronstory · 06-06-2021, 16:34

Page 46 of the manual says it's a power/alarm connector. What is the plug your unit has to the left of it? It's not in the manual.

https://em-trak.com/wp-content/uploa...-manual-EN.pdf

newbie- · 06-06-2021, 17:48

Quote:

Originally Posted by ronstory

Page 46 of the manual says it's a power/alarm connector. What is the plug your unit has to the left of it? It's not in the manual.

https://em-trak.com/wp-content/uploa...-manual-EN.pdf

Yeah this is the one I mean. My paper manual that came in the box has it but I couldn't find anything in there that labels it.

ronstory · 07-06-2021, 09:08

Interesting. You have an extra connector to left of the mystery connector. What is it attached to? Power?

tanglewood · 07-06-2021, 16:38

I think it is indeed N2K, but I suspect it's inactive. Or just give it a try. My older Comnav manual for the same device shows the connector, but doesn't explain what it is. I seem to recall reading somewhere that it was "for future use".

I think N2K, even if present on a Class A AIS, is of limited use. The governing IEC and IMO standards mandate the use of 0183 (actually the IEC equivalent). N2K is not allowed for any of the required functionality. On the devices I've looked at that do have N2K, it's typically output only for target info, and is in addition to the mandated 0183 outputs. I believe all the mandatory sensors have to come in over 0183.

Notright · 09-02-2023, 06:02

Trying to find a power cable for a100 or the live and neg pin

SailingHarmonie · 09-02-2023, 12:45

Almost none of the recreational boats I come across with a Class A AIS have it configured properly and with properly updated data while at sea.

So often purchased without understanding, other than “Bigger! More Expensive! Must Be Better!”