Garmin Oddity

[stwendl]

I have a 7612 and vhf200 on my R27. 2 weeks ago I upgraded the firmware from the Aug 2016 version early may 2018.

After the upgrade the VHF shows as coordinates among others that I was 922.xxx degree E and was going 99kts while parked in my slip. the 7612 showed proper coordinates and speed, just the VHF 200 did not. I also have a N2K monitor which showed the latitude and longitude to be the SAME value like 214degrees. See pics in my album.

contacted garmin which seemed to be a bit slow getting started on this issue. Some of their suggestions was to "change the VHF antenna", and "connect via nmea 183", or "wait for next release in june". I had expected a bit better responses from them. They did offer to replace the HW, however, I assume it is bad Software.

Everything was fine before the upgrade, which went fine. It looks like this bug repeats longitude and latitude as the same value, and longitude has has 800 added to the its value to show east east vs west, at least my protocol analyzer shows this.

 

[Cessna172]

Was the VHF radio "on" when the update was done?

 

[stwendl]

yes it was, because the software on it would be upgraded as well if there is a new version available. The upgrade is done via a sd card from the 7612. I have done this before, 2 years ago, without any issues.

 

[RProffer]

When ever I had an issue with my Garmin, I found that if I reinstalled the update the problem would get fixed.

 

[stwendl]

Update. I am in contact with garmin about this issue with varying degree of understanding of their support staff. If you have a garmin version before 11.0 I would recommend not to upgrade, unless it fixes some issues that you need, until garmin addressed this issue.
The following was communicated to garmin support today and I am waiting for a response.




Further testing and multiple updates to latest revision as of May 18th (V11.20) revealed the cause of the erroneous display.

My boat is parked under a covered roof made of metal flashing blocking reception somewhat. As soon as the boat moved out of this covered area the VHF200 showed proper coordinates. Mind you that the 7612 showed proper coordinates even under the covered slip but for some reason transmitted garbage on the N2K bus. My reasonable expectation is transmission of last good coordinates not erroneous and false data and, as far as II recall, this was how the original version 8.20 operated.

So when poor or no gps reception situation occurs then the data on the N2K bus is no good and in fact FALSE. I think your sw engineers should take a careful look into the logic of when and what data is repeated on the N2K bus. According to my analyzer the data was transmitted with the N2K source id of the 7612 and alternated between 214 degrees and 922 degrees on BOTH longitude and latitude, wrong time and high speed. At first I thought this was a result of the upgrade and memory was not properly initialized due to no GPS lock, however after a short trip and returning to covered slip the wrong data was transmitted again on the bus suggesting some wrong logic in the code.

My expectation is the transmission of the last good position and not a bogus one. Imagine the GPS antenna gets damaged and no lock can be obtained, emergency data would lead recovery crew to a a complete WRONG location if DSC was activated. I can't imagine it is the intent of garmin equipment to mislead recovery efforts in such a way.