Raymarine C80, SLR200 and new radio

[Phil Renouf]

I have no doubt that the answers I need are already discussed somewhere here but I lack the knowledge to look for it. I have recently replaced a disfunctional radio with an Icom IC-M330. AIS duties are provided by an SLR200 and nav by an old Raymarine C80. The original radio was linked to the others by an imaginative bit of cable splicing which I could not understand. To simplify matters, I disconnected the new radio as it has its own GPS feed and I reasoned that simplifying things would allow me to get the rest working again until such time as I could understand how to add complexity. I thought that feeding AIS data into the C80 might be all I need to do but evidently that is not so simple. I know that the SLR can receive other data and send it out at 4800 baud with the AIS data so, I'm kind of thinking that feeding in the DSC from the radio might be a good thing before it is passed on to the plotter. But I also think that I haven't got anything right so far and maybe should stick to growing tomatoes. I really need someone who knows what I should do, how I should do it and has the patience to put it into words of fewer than two syllables. Anyone can do that?

[Tehani]

Originally Posted by Phil Renouf

I have no doubt that the answers I need are already discussed somewhere here but I lack the knowledge to look for it. I have recently replaced a disfunctional radio with an Icom IC-M330. AIS duties are provided by an SLR200 and nav by an old Raymarine C80. The original radio was linked to the others by an imaginative bit of cable splicing which I could not understand. To simplify matters, I disconnected the new radio as it has its own GPS feed and I reasoned that simplifying things would allow me to get the rest working again until such time as I could understand how to add complexity. I thought that feeding AIS data into the C80 might be all I need to do but evidently that is not so simple. I know that the SLR can receive other data and send it out at 4800 baud with the AIS data so, I'm kind of thinking that feeding in the DSC from the radio might be a good thing before it is passed on to the plotter. But I also think that I haven't got anything right so far and maybe should stick to growing tomatoes. I really need someone who knows what I should do, how I should do it and has the patience to put it into words of fewer than two syllables. Anyone can do that?

It is necessary to carefully read the characteristics and installation manuals of all the devices.

The output of your SLR-200 (brown and yellow wires) is NMEA0183 at 38400 baud. You will need to set a C-80 NMEA0183 channel (input) to that speed so that they can communicate.
The input of the SLR-200 (gray and black wires) are NMEA0183 to 4800. You can connect them to the NMEA0183 output of your ICOM radio, but I don't think it will be useful for what I explain below:

- This AIS receiver already integrates a GPS receiver. It is not necessary to provide you with such data.
- In theory, this GPS data will be transmitted to the C-80 also at 38400 baud in combination with the AIS data.
- It is possible that the C-80 accepts any type of data at 38400, but I'm not sure (eg Garmin does not).
- If you have a Raymarine Raystar antenna connected to the C-80, disconnect it to test. And if the test is successful, you'd better remove the Raystar altogether because it's a worse GPS receiver and its internal battery will be dead or about to die.

The DSC message standard was published in a rather confusing way. For this reason, each manufacturer has understood it in its own way and devices from different manufacturers are not usually understood. In any case, the DSC are two-way messages and their configuration (SLR-200) does not allow sending from the plotter to the radio. (You could investigate the RS232 connection of the SLR-200, because the manual doesn't explain anything).

I wish you luck.

[Phil Renouf]

Tehani, your response was insightful though I will need to take some time to understand it fully. It is particularly frustrating that the combo with the old radio provided AIS data to the C80 before but now it does not. I will try to make sense of it with your guidance though I accept now that I may need to buy the expertise of an electronics expert - I prefer to understand systems myself so will persevere for the time being.

[Tehani]

Originally Posted by Phil Renouf

Tehani, your response was insightful though I will need to take some time to understand it fully. It is particularly frustrating that the combo with the old radio provided AIS data to the C80 before but now it does not. I will try to make sense of it with your guidance though I accept now that I may need to buy the expertise of an electronics expert - I prefer to understand systems myself so will persevere for the time being.

I'm still studying your case.

I am sorry to tell you that your new ICOM radio does not have a built-in GPS receiver. And this is a problem because one with an output speed of 4800 baud must be connected.
You have two solutions to solve your problem:
1- Connect a new GPS receiver to the radio and to the AIS (4800), and leave the AIS connected to the C-80 as it was.
2- Use a gateway. This can increase the overall performance of your installation (WiFi, Seatalk, etc).

Luck!
Jose Luis

[Phil Renouf]

Originally Posted by Tehani

I'm still studying your case.

I am sorry to tell you that your new ICOM radio does not have a built-in GPS receiver. And this is a problem because one with an output speed of 4800 baud must be connected.
You have two solutions to solve your problem:
1- Connect a new GPS receiver to the radio and to the AIS (4800), and leave the AIS connected to the C-80 as it was.
2- Use a gateway. This can increase the overall performance of your installation (WiFi, Seatalk, etc).

Luck!
Jose Luis

Yes, the radio does have GPS though checking on the box I see the full model designation is IC-M330 GE (the GE is not included on the front of the radio!). I have changed baud rate for the C80 to 38400 and have checked output of the SLR200 for polarity to ensure that input to the C80 is correct (as far as I can ascertain with a small multimeter) but still no joy.
I have contacted Comar Systems to see if anything more can be done with my limited multimeter to be more certain that the unit is functional but am finding it very frustrating that it all worked before the old radio failed. I can't see that what I have now is anything other than simplified compared to what was working before yet, so far, no AIS.
I should have stuck to gardening!

Phil

[goboatingnow]

What you are doing is fine so it’s probably a wiring issue.

While the SLR can multiplex the data from its nmea input at 4809 onto the output at 38400 I’m not sure the C80 can process anything other then the ais sentences.

As you say the Icon has a GPS receiver built in with an external antenna

[Phil Renouf]

...and, just like that the issue is fixed.

The advice I received here on this forum was very valuable however the help I received from Comar Systems was what I needed to understand exactly what the issue was. I will copy and paste their wise words here for anyone who has an interest:-

"Firstly, if you see the red channel A and B LEDs briefly flashing it is a very good sign as it means your unit is receiving valid massages.

As you say the input baud rate of the plotter wasn’t set to 38400 and you had to set it up, what was the baud rate set up to before? It might be that your SLR200 is set to a baud rate of 4800. If you open the unit you should see two PCBs inside. The bottom PCB should have a jumper link which shows the two baud rates 4800 and 38400. If this is set to 4800 change it to 38400 and test your setup again. Check the polarity of your NMEA cables is correct. Swapping them does not damage the in- or outputs so you could just swap them to see if they were the wrong way round.

If that all does not help, there is a simple but very effective test using just a red LED if you can get one: Link. This should confirm that your output is definitely sending out data… or not."

Indeed the jumper was set to 4800 baud and I would not have known that without their instruction to open the casing. So. plotter returned to 4800 so that it can receive data correctly, a bit of neat soldering to tidy up connectivity and I now have a system that warns me of perilous hazards from all corners of Ramsgate marina.

[smac999]

are you saying your c80 plotter is showing ais targets with the port set at 4800? I have never seen ais data sent at 4800 baud before.

[Phil Renouf]

Originally Posted by smac999

are you saying your c80 plotter is showing ais targets with the port set at 4800? I have never seen ais data sent at 4800 baud before.

Yes, the C80 is receiving AIS at 4800 baud and was set up like this before I started messing with it. I have reverted to these settings because I knew it worked though I don't know how if the slow baud rate is particularly efficient. Still, it is now functional and I have the option to set it at the faster rate (the C80 is not sending NMEA out) if I think it would improve things.