IF-NMEA2k2 output

Snorre

New member
Hi

I have an issue with my NMEA-network.

My set up: TZTl12F + GP700 + Garmin 700-series + AIS-transceiver + VHF, all devices are connected to nmea2k network.
Ais uses an IF-NMEA2k2 in AIS-mode.
VHF uses an IF-NMEA2K2 in standard 4800 mode for GPS-data to VHF and DSC-data to NMEA2k network.

AIS transceiver delivers AIS and positions sentences to IF-NMEA2k2. VHF receives position from it's IF-NMEA2k2 as long as only AIS and VHF are turned on.

VHF receives position (RMC & GGA) form IF-NMEA2k2, but when TZT2 is turned on, the lat/lon data disappears form the RMC sentences and GGA sentences disappears completely from the VHF's IF-NMEA2k2 output. If TZT2 is set up to send GNSS PGN, lat/lon reappears in the RMC-sentences. When TZT2 stop sending GNSS-PGN (turned off og GNSS-PGN disabled) lat/lon disappears again.
At this point I expected the VHF - IF-NMEA2k2 to provide RMC (and GGA?) with lat/lon to the VHF, like it did before I turned on the TZT2 since AIS is still delivering GNSS-PGN to the network. It does not... If I restarts the VHF's IF-NMEA2k2 it start to deliver RMC and GGA sentences again.

Any suggestions to how to avoid restarting the VHF IF-NMEA2k2 device after TZT2 have been active on network? Is the IF-NMEA2k2 programed to preferring PGN's form Furuno sources?

It seems like the IF-NMEA2k2 will not pick up GNSS-PGN form other sources than TZT2 form the moment the TZT2 become active on the network...

Turning on or off the old Garmin plotter does not affect the out put form the VHF IF-NMEA2k2. The IF-NMEA2k2 connected to the AIS-tranceiver have delivered AIS PGN's uninterrupted to the network for 10+ months with out any issues...
:furuno

(Sorry for the long post)
 
The IFNMEA2k2 takes it's marching orders on which source it uses from the TZT2. If you wish to always use the AIS as your GPS source, then you must change it to be your primary source of data in the TZT2 also. Ideally, the AIS is an AIS unit and not designed to be a primary source of GPS. Typically another external GPS or the internal GPS of the TZT2 would be a better source if picking up well. If you wish the TZT2 to be the primary source, then you will need to turn on the needed data to output, so it can reach the radio. I believe your issue relates to the fact the IF-NMEA2k2 is getting GPS from the AIS when the TZT2 is off. Then you turn on the TZT2 and it's source is setup for the internal GPS. Hence it tells the IF-NMEA2k2 to use the same source; your GPS source is switching sources when you turn on the TZT2.
 
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