D180 to GTX330 altitude encoding

[moffie999]

I have just installed a new D180 and interfaced it with my GTX330. All seemed to be working correctly, but today I discovered that if I fly above FL72 (7200 feet) the altitude sent to air traffic generally descends as I climb but is inconsistent in this. Some random climbs/descents are sent by the GTX330.

Anyone know why this might be happening since all is OK below FL72?

 

[Etienne]

Hi Neil

Are you using the serial stream (two wires), or going Gilham (lots of wires) via a converter?

Thanks
Etienne

 

[moffie999]

Hi Etienne

I connected a wire from pin 13 on the D180 to pin 24 on the GTX330 and also grounded pin 21 on the D180 as instructed in the D180 installation guide. I used Format 4 / Baud rate 9600 / Icarus input on the GTX330.

 

[Etienne]

Unfortunately that does make it a bit more baffling. With a serial connection, either it works, or it doesn't. This would only leave a protocol issue, but if I remember correctly, those settings that you've got there are correct.

I'm out of ideas, and can only suggest waiting for dynonsupport to reply...

 

[moffie999]

Thanks Etienne - I have also sent an email to the Dynon support team

 

[dynonsupport]

Hi Neil,

We're a bit baffled too. As Etienne said, it either works or it doesn't. Is there any other device hooked up serially to the 330? I seem to remember that it may have more than one serial input.

Since you've already gotten in touch with tech support directly, we'll let this thread continue over direct email.

 

[moffie999]

Thanks for the replies folks.

I think I may have found the problem - I re-racked the GTX330 this morning and then everything seems to be fine. I was unable to climb above FL85 today due ATC but the readouts were correct up to that level.

I can only assume that the unit was not making contact with all pins in the connectors properly. Would you agree that is possible, or do I have an intermittent fault?

There are no other units connected to the 330, only the D180.

Cheers

 

[jakej]

Either way it's intermittent - I haven't seen the 330 units yet however the 327 looks very similar (rack wise) and they don't have a 'connector' issue. Maybe it just wasn't seated home properly in the first place ?

The only other unit that does have this rack issue is the Garmin 480.

Jake J