A frustrating GNC255 / Aera 660 mystery - solved

Katamarino

Katamarino

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Katamarino
I'm wrapping up installation of a new GNC255A nav/comm. One of the nice features offered by this radio is that one can push comm frequencies from my existing touch-screen panel-mounted Aera 660 to the standby comm position of the GNC255A. Very convenient.

Unfortunately, we just can't get the feature to work.

On the hardware side:

GNC255A connector 1, pin 1 (RS-232 out) is wired to the Aera 660 purple wire (RX 2 data in)
GNC255A connector 1, pin 16 (RS-232 in) is wired to the Aera 660 orange wire (TX 2 data out)
GNC255A connector 1, pin 31 (RS-232 ground) is wired to the same ground as the Aera 660 is grounded to and connectivity has been confirmed.

On the software side:

GNC255A Serial data format is set to NMEA
Aera 660 data port 2 format is set to Aviation In/NMEA & VHF Out

The software of both units is up to date. According to the manual, we should now be able to tap on a frequency on the 660 and it should populate to the 255 standby; but nothing at all happens.

Garmin tech support have said that all the hardware connections and software settings seem correct. They have suggested:

- Replace the 660 cradle; I have a new one arriving Tuesday. This seems like a long shot though.
- Disconnect the Aera 660 data 1 wires from the existing IFD540 (it's connected through MapMX) and see if we can get the 255 connection working through data 1 instead of data 2. We'll try that next week.

If anyone has any experience with these, or bright ideas, my installer and I would be grateful.

Aera manual: page 196 of the PDF is the relevant one.

GNC manual: page 6-3 is relevant. Although this is an older revision of the manual, this section is identical to the latest revision and I can't find a public version of the latest one.
 
I have found the problem.

There's a bug in the Aera software. If data 1 format is set to MapMX, then frequency pushing from data 2 doesn't work. If you set data 1 to "none", data 2 works fine.

Apparently this is a bug that numerous other pilots have come across that was introduced in software 3.70, but Garmin aren't acknowledging.
 
I have to send my aera in for a new one, Garmin seems happy to help, but they do take about a month to respond to emails. It’s a pain in the back.
 
Katamarino said:
I have found the problem.

There's a bug in the Aera software. If data 1 format is set to MapMX, then frequency pushing from data 2 doesn't work. If you set data 1 to "none", data 2 works fine.

Apparently this is a bug that numerous other pilots have come across that was introduced in software 3.70, but Garmin aren't acknowledging.
Click to expand...
Does it still push "nearest"? Or is all frequency pushing broken?

Also, what version firmware are you running?
 
I'm running version 4.00 on the Aera. I'll check that the "nearest" function is working once we get the airplane back in the air, hopefully this week.
 
My 660 pushes fine to a gtr200b (I think that is the radio anyway). Works great.
 
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