GP 32 replaced by GP 39 / Connection with NKE Gyrographic

Giovanni

New member
Hello, I had a GP32 well connected with the NMEA 183 of a very old NKE Gyrographic: connections were White and Blue of GP32 with Yellow and Green of Gyrographic.
I have now purchased a new GP39, and connections are unchanged, according to the connections schemes, but the NMEA 183 channels are not created after reinitialization of NMEA on the Gyrographic.
  • The oldest NMEA version 1.5 is selected on GP39, together with the option "Rem1"
  • Waypoint is set on GP39 before reinitialization of the nmea
  • Data are correctly sent out from GP39 to VHF DSC
  • Data are not displayed on the NKE Gyrographic
Is there any compatibility problem due to RS422 standard opf GP39? (was the GP32 base on RS232?)
Is there any compatibility problem due to an update of the NMEA 1.5 sentences done by Furuno on GP39?
Is there any compatibility problem due to some update of the GP39 software / CPU?
Thanks!
 

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You are correct that the RS422 output is still White (TD+) and Blue (TD-)
GP39 is RS422 only
Try NMEA v2.0 and/or REM2 or GPS to see if it makes a difference
It's always best to update to the latest version of software before spending a lot of time troubleshooting. Please ensure you have the latest version for the GP39. Here's a link to the page with the software on it: https://furunousa.com/en/support/GP39
 
Unfortunately I didn't manage to solve the problem yet. I recap below the issue.
Can someone help me to identify a solution?
Thanks!
  • I had a GP32 that transmitted data to an NKE gyrographic screen. The white and blue wires of the GP32 were connected to the yellow and green wires of the NKE, respectively. It works perfectly.
  • I purchased the Furuno GP39 GPS and used the same connections I already had (and this is also consistent with the Furuno connectons diagrams).
  • I set NMEA183 v 2.0 on the GP39 / Rem1 (I also tried other NMEA options: 1.5, AP, Rem2).
  • I reinitialized NMEA on the NKE screen, but the channels with the GP39 data are not created.
  • However, the GP39 transmits data to the VHF DSC radio very well
  • Everything returns to working perfectly when I reinstall the GP32 and initialize NMEA.
 
Try disconnecting the VHF connection so that you only have wht/blu from the GP30 going to your NKE screen. See if that works.
 
Thank you, I have disconnected VHF already, but it doesn't work.. Furthermore, when I install back the old GP32 everything works perfectly, no matter whether the VHF is connected or not.
Do you know whether, further to the white and blue, should also the ground be connected somewhere (e.g. with the black wire) to have a "zero" reference?
 
I was thinking a voltage/RF level was being affected by having both connected.
Ensure that you don't have anything wired to the yellow and/or green wires on the GP32 cable. If not, then try connecting the bare shield wire to a dedicated bonding system (for example Dynaplate) or to DC- (same connector as black wire in cable) to see if that helps. I only say that based on the interconnection diagram you posted above. Finally, another option is try connecting through a NMEA expander box.
 
Hello, I have conducted a "self tst/system test" (see attached image) on the Furuno GP39 and it appears that Data1 is "NG", which means "no good". My interpretation is that the GP39 has some malfunctions.
Is the above also your understanding?
Thanks!
 

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That is a normal indication because the Data1 test is for factory testing. Is the GP39 showing the correct date? If not, change Menu-GPS Setup-Rollover to 2034.
 
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