DSC positions on GP1670F

[tasdev]

I have an ICOM VHF M604A radio (NMEA0183 interface) and a GP1670F plotter (NMEA2000 interface). With an IF-NMEA2K2 bus converter, GPS position info from the plotter is correctly sent to the DSC radio. On an incoming DSC call, positions are registered correctly on the radio but not shown on the plotter.
The Icom radio software is up to date . I have monitored the NMEA0183 output from the radio when it is called, and the expected DSC/DSE sequences are being generated. The plotter does not plot these positions on the screen, or even register that a DSC call has been received, and the PGN 129808 does not appear on the plotter traffic monitor. The IF-NMEA2K2 software is up to date. It makes no difference if the IF-NMEA2K2 is replaced by an Actisense NGW-1 running the latest software release (the newest version handles DSC/DSE conversions) so the problem seems to be in the plotter ( also running the latest software). It looks as though the plotter will accept DSC info when it comes direct from an NMEA2000 radio, but not after the identity of the sender has been altered by a bus converter. Does anyone have a fix for this ?

tasdev

 

[Johnny Electron]

viewtopic.php?f=3&t=2513&p=20697&hilit=dsc+dse#p20697

viewtopic.php?f=4&t=3967&p=15165&hilit=dsc+dse#p15165

 

[tasdev]

Has anyone with a "native" NMEA2000 VHF set (no bus converters involved) actually got DSC/DSE positions to display on a GP1670F ?

 

[tasdev]

UPDATE: With a second IF-NMEA2k2 on the N2K bus, the 0183 output of the second converter shows the full DSC/DSE
message from the VHF is getting onto the N2k bus, EXCEPT that the sender ID is now shown as "GP". No-one on this site has said they've got this setup actually working, and if the plotter is seeing a message purportedly from itself then it won't respond! There is a note in the 'software history' about changing sender ID's, which may now be preventing proper operation. Software fix needed?

 

[Johnny Electron]

The IF-NMEA2k2 used to use a $II talker but newer software uses $GP; this is for 0183 not NMEA 2000 talker.

 

[tasdev]

Thanks Johnny,
Can you clarify which way round that last bit works for me please? My "talker" here is the 0183 VHF set. When the DSC/DSE message is converted, will it appear to the plotter on the N2K bus to be coming from $GP or $CD ?

 

[Johnny Electron]

NMEA 2000 doesn't use talkers like NMEA 0183. NMEA 2000 uses PGNs. The Furuno IF-NMEA2k2 can converter DSC/DSE into standard PGN 129808. You must have both the DSC and DSE provided because you can't plot the target information without both sentences being provided to the converter.

 

[tasdev]

As well as the PGN, there is a functional source address (=sender ID) contained in the header of every transmitted N2K frame. My second IF-NMEA2K2 decodes the N2K bus message back to NMEA0183, reproducing perfectly the original full DSC+DSE input(both parts) from the VHF, except that the sender ID is changed.
So a complete 129808 PGN message is getting onto the N2K bus, but possibly with a modified source address.
The GP1670F (DSC input selected as 'AUTO') is not registering this 129808 message, and it does not appear on the GP1670F's CAN bus monitor. Do the IF-NMEA2K2 and the GP1670F have incompatible software?

 

[Johnny Electron]

Not that I am aware of. What version of software are you running in the GP1670F and the IF-NMEA2k2?

 

[tasdev]

GP1670F is running V2.0.4.60.

IF-NMEA2K2 is running V.01.16:01.01

 

[Johnny Electron]

I suspect your radio doesn't have the newest firmware and maybe something isn't correct with the 0183 sentences (DSC/DSE) that is provided. I tested the IF-NMEA2k2 with the GP1670F and they work fine when the proper sentences are received by the converter. You might want to check with ICOM about your firmware level in the radio.

 

[tasdev]

Thanks for that. I was told by Icom a couple of years ago that there were no "software" updates available for the M604A, but that may have been interpreted too narrowly. I'll go back to them and ask specifically about "firmware" instead.

 

[tasdev]

Icom (Australia) have now advised that there have been no updates at all for the M604A.
The "IC-M604A/M802 firmware upgrade" referred to on the MarineCommander website is apparently fictitious.