Dynon Encoder Question

We have a D180 and D100 with the Garmin 345 xponder and a 530W. This setup has been working fine for a few months now, but on a recent flight, the 530W threw an error message about not receiving altitude info. After a little in-air troubleshooting, I realized the xponder was showing "-----" on the pressure altitude readout, and ATC confirmed that they weren't receiving my mode C. At this point, I'm assuming the encoder is the problem.

I have an email out to Dynon, but sometimes VAF comes through much quicker. Does anybody know how to check the functionality of the Dynon encoder? I can see where you can change a few settings, but I didn't see any way to see if it's working or what it's sending out. And if the encoder did go bad, is that a replaceable part on these units?

Thanks!

The dynon outputs serial info via a 232 line (no "encoder'), failures of 232 outputs are rare so I'd be more inclined to make sure the wiring is good. Of course there is also the possibility they used the old gray code converter that Dynon used to sell, if so there could be a problem with that unit. You can have 232 or gray code going to both the xpdr/530.

Follow up

I realized I never closed the loop on this problem for any future readers...

Dynon was surprised, because they said failures of the altitude signal are rare. But they really don't have a way to check it or to see what's being sent out. Luckily for us, the D180 and D100 are both capable of sending the altitude info. In our case, the D180 was sending it. We took the wire out of the D180 and connected it to the D100, and everything is back to normal. So for us, it was a really simple fix.