Icom Radio NMEA 0183 Interface

VHF Marine Band radios, protocol, radio communication theory, practical advice; AIS; DSC; MMSI; EPIRB.
porthole
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Icom Radio NMEA 0183 Interface

Postby porthole » Wed Mar 30, 2016 6:45 pm

One of my VHF radios is a Icom IC M-504. Here is the manual: Icom IC M-504 manual

Last season I had this set as my DSC distress radio. My Northstar 952 was interfaced with the Icom to provide position and time data.
The radio worked fine and always displayed the Northstar's position and time on the main screen.

This season I replaced the Northstar with a a second HDS Gen3. This was the only change to the the VHF and Chart plotter set-up. Now, I cannot get the radio to display position data. I have tried outputs from both HDS units and both ports. I even went as far as to hook up the Northstar, which still has the NMEA 0183 connections on the data cable from when it was removed, the Northstar' took a while to [get a position fix], but even after an hour I still have no position data.

Is there a way to test data output on a NMEA interface?

Is there a way to check the VHF to see if there is any data coming in to the radio?

Stumped.
Thanks,
Duane
1999 Outrage 21
1999 Yamaha SW Series II 200

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Barnacle
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Re: Icom Radio NMEA 0183 Interface

Postby Barnacle » Thu Mar 31, 2016 12:23 am

I had a similar problem when I tried to interface my Garmin 70dv to an Icom 412. The solution for me was having to go into the network settings of the Garmin and set both the input and output NMEA 0183 serial ports to "open". Might be something to look into with your HDS Gen3. Hope this helps.
"Hoosier Gal" - 1986 Outrage 20 / 2005 Yamaha OX-66 EFI 200hp
"Whipray" - 1976 Herreshoff Meadowlark 37 / 2014 Beta Marine (Kubota) 30hp

porthole
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Re: Icom IC M-504 VHF and NMEA 0183 problem ???

Postby porthole » Thu Mar 31, 2016 10:02 am

[The solution is] not [to be found in] a Gen3 setting.

The 0183-only Icom and 0183-only Northstar were connected as they were originally and still did not work.

[HDS] Gen-3 settings seem to work a bit differently, anyway.
Last edited by porthole on Thu Mar 31, 2016 9:43 pm, edited 1 time in total.
Thanks,
Duane
1999 Outrage 21
1999 Yamaha SW Series II 200

jimh
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Re: Icom Radio NMEA 0183 Interface

Postby jimh » Thu Mar 31, 2016 4:00 pm

To test the NMEA-0183 TALKER signal from a device, connect the NMEA-0183 TALKER signal to a terminal. Set the terminal parameters to match the NMEA-0183 parameters. The terminal will display the data being sent. You can find the serial data parameters in my article at

http://continuouswave.com/whaler/refere ... A0183.html

under the subheading "Configuration of baud rate and other details."

If you have an older personal computer, it probably has a serial port interface. If you have a newer computer, it probably does not have a serial port. In that case use a USB-to-RS-232 Serial adaptor. The USB-to-Serial adaptor I use is the USA-19HS from KEYSPAN.

Make the NMEA-0183 interconnection to an RS-232 port as follows:

NMEA-0183 SIGNAL --- CONNECT TO RS-232 TERMINAL
TALKER A --> RxData (DB9-Pin-2)
TALKER B --- no connection
LISTENER A <-- TxData (DB9-Pin-3)
LISTENER B <--> Signal Ground (DB9-Pin-5)


For a terminal, if on some variety of Windows, look for some terminal application; if on MacOS, open a command line prompt; at the $ prompt enter the command

screen /dev/cu.yourDeviceNameHere 4800


If you do not know your device name, run

ls /dev/cu*

and figure out what the device name is from the list.

ASIDE: the UNIX command cu is a very old command; it means call up another system, that, is open a modem connection to it.

I do this all the time to test NMEA-0183 devices. I use a USB-to-Serial adaptor with a short cable wired to connect it to my Universal NMEA-0183 Interface standard, and I have a short AppleScript that calls up the terminal.

The problem for you will be to first prove the test method is working, then to use the test method to test a device.

jimh
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Re: Icom Radio NMEA 0183 Interface

Postby jimh » Thu Mar 31, 2016 4:24 pm

The general problem with serial digital communication interfacing is along these lines:

--are the physical connections properly made? (subject to user control)

--are the electrical signal parameters between the devices compatible? (usually set by the standard in use)

--do the two devices agree on their logical meaning? (usually set by the standard in use)

--are the devices configured to a mutually compatible set of parameters for sending those signals? (subject to user control)

--is the sending device clear to send signals and the receiving device ready to receive signals? (usually set by the standard in use)

--is the sending device sending data in a format that the receiving devices understands? (usually set by the protocol being sent over the connection, but often can be affected by the user configuration)

--can the receiving device pass on this data to some application that can use it? (usually set by the devices themselves)

Any mistake in this seven-layer cake and there is no communication. Serial data communication is really quite complicated.

UPDATE: I expanded the analysis to show who controls each element of the connection. The user is primarily able to control how the interconnection is physically made, that is, what wire is connected to what wire, and able to control some settings in the communication protocol, such as number of bits, data rate, stop bits, and so on. The rest of the elements of the connection are generally set by the devices involved and the standard used by those devices. The user is also able control in some cases the type of data being sent across the connection. I discuss more about these elements of making a successful serial data connection in my article Guide to NMEA-0183 Interconnections.

porthole
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Re: Icom Radio NMEA 0183 Interface

Postby porthole » Thu Mar 31, 2016 9:45 pm

jimh wrote:To test the NMEA-0183 TALKER signal from a device, connect the NMEA-0183 TALKER signal to a terminal. ...


Sounds like an interesting project. I still have a Windows 98 laptop with a serial port that I keep around for tuning my bike's fuel injection and spark.
Thanks,
Duane
1999 Outrage 21
1999 Yamaha SW Series II 200

porthole
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Re: Icom Radio NMEA 0183 Interface

Postby porthole » Thu Mar 31, 2016 10:05 pm

Solved [the problem of lack of NMEA-0183 communication between devices]. Part of what had me stumped was the Northstar and the Icom had communications. They were working as expected when I winterized the boat, then I removed the electronics for the winter. Between my upper electronics cabinet and the area behind the console I used two 10 position terminal strips. The strips are connected through the T-Top piping with three pairs of shielded two-conductor cable (red, black, shield). These are labeled A, B and C. The Icom and Standard VHF's and the two HDS Gen3's are then inter connected through these strips. I tried several different connections and could not get data to the Icom

When I could not get the Icom to receive the data I used my my previously working Northstar 952. That did not work. After fussing with that for some time I gave up. Was considering just buying another GHX-2200 and connect it separately to the second HDS. Playing around in my garage, I found one of the new-out-of-the-package Radio Shack jumper leads was defective! No wonder the Northstar didn't work.

Reconnect the Northstar and as soon as it locked onto a signal the Icom display position data. Now I know the radio 0183 listens.

Back to the connections for the HDS to the Icom. Still not working. I went back into the second HDS network setting page and changed 0183 Port 1 baud to 4800, instantly the position data popped up on the Icom, and at the same time the AIS data was lost on the first HDS. Checking number one HDS the port baud rate changed to 4800 from 38400.

It took several back-and-forth attempts with the network port setting pages and even turning one unit off while adjusting the other, but eventually each unit kept its respective baud rate, and the Icom has data.
Thanks,
Duane
1999 Outrage 21
1999 Yamaha SW Series II 200

jimh
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Re: Icom Radio NMEA 0183 Interface

Postby jimh » Fri Apr 01, 2016 10:40 am

Your problem was in the first tier of communication I mentioned above: a physical problem, that is, a wire was not connected. This is the simplest problem to overcome and often the most likely cause of no communication.

porthole
Posts: 599
Joined: Tue Oct 27, 2015 9:57 pm
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Re: Icom Radio NMEA 0183 Interface

Postby porthole » Fri Apr 01, 2016 11:48 am

Correct with the wire not connected. But I still needed to overcome the baud rate settings.
True test will be tomorrow when I turn everything back on and see if they all communicate after a day of rest.

Then I add more to the mix; fuel flow sensor and fuel level sensor [but they are on a NMEA-2000 network and not on a point-to-point NMEA-0183 interface between the radio and a GNSS receiver source.]
Thanks,
Duane
1999 Outrage 21
1999 Yamaha SW Series II 200