View Full Version : Digitrak to Vision PMA

Jonathan Alvord
03-29-2020, 07:13 PM
Ok my old digitrak needed to be replaced (Screen unreadable, and Pitot/Static shot) Was told by mid Continent that it would be easier/cheaper to replace the old with new Vision PMA and would only require changing the power wire. The new unit does not recognize the GPS and thus only does bank angle, and not tracking angle ( I had not messed with any wires/inputs on the GRT), it does not recognized the stick on button (it does turn off).

I spoke with GRT and they said to track down the wires from the autopilot to figure out what port it is plugged into, but gave no guidance Ast to which pins go to which ports other than look it up in the manual which for I can't seem to find in 4 different manuals (installation/operations) for the GRT/Vision/Digitrak.

I did find that Port 5 is empty and will try to set that for the autopilot, just frustrated as this was supposed to be a direct replacement.

I just want my plane back like it was! haha.

03-30-2020, 08:44 AM
I have a Vizion PMA at the local FedEx sort facility, for delivery later today. It's supposed to be coming with a short d-sub adapter cable that corrects pin outs, making it almost plug-n-play.

I have a few other concerns as well, e.g. settings (including whether they are accessed the same way as the Digiflight), software versions (manual says my GNS430W should be running 5.20 or 5.30, depending on what software version in in the Vizion; mine is 5.10), etc... Fingers crossed.

I'm going to open the panel and remove the Digiflight today. Depending on timing of the delivery, the Vizion may not go in until tomorrow. I'll update you post install.

Jonathan Alvord
03-30-2020, 10:37 AM
Not sure you need the adapter. If you can remove pins it is very easy to move pin 6 (power for digitrack) to pin 19 (power to vision) all other pins are supposed to remain the same.


03-30-2020, 10:38 AM

Are you replacing a DigiFlight II VSG with a Vizion PMA?

From the Vizion troubleshooting guide, no GPS is most likely because the baud rate of the Vizion is not the same as the baud rate of your GRT. GRT usually uses 9600 baud so the Vizion must be set to that also. Baud rate is in the Lateral Setup pages of the manual.

The wiring is pretty similar.

DigiFlight II has +12 on pin 6 and optionally pin 19 while Vizion has +12 only on pin 19.

Vizion pin 6 is a Pitch trim input from the servo and likely not required.

You should have +12 only on pin 19 of the Vizion and no connection to pin 6 of the Vizion.

So if your DigiFlight install had +12 on pin 6 and not also pin 19 that could be the problem. I don't think this is the case since the Vizion powers on. Be sure there is no connection to pin 6 of the Vizion or if there is it should be from pin 8 of the pitch servo.

Hope this helps.

Jim Butcher

03-31-2020, 10:57 AM
Well, the saga continues. FedEx delivered my Vizion yesterday, as scheduled. The bad news is that the adapter was inadvertently omitted from the shipment. :( Hopefully, one will be shipped today, for overnight delivery. It is my understanding that the pin changes are relatively minor, but at least in my case, the d-sub that plugs into the AP controller doesn't have enough slack to access it without significantly more involved panel disassembly.

03-31-2020, 11:22 AM
I did the upgrade from a TT Digiflight to a Vizion 385 last fall. I was able to get it done before the TT-Bendix transition was completed. TT shipped me a jumper harness as the connectors are different. I could have rebuilt the connector but since they supplied it for no additional charge I took it. I have an Avidyne IFD440 driving the A/P through an ARINC unit to the GRT Sport SX, I also have a switch to drive the A/P directly from the Avidyne.
It works perfectly although there was a learning curve to how it functioned Vs the old Digiflight.

03-31-2020, 02:49 PM
Well, I spoke with Mid-Continent. Doesn't look like I'll be getting the adapter anytime soon--they're out of stock. If they hadn't told me it would be shipped with the controller, I wouldn't have opened up the panel. Sigh... :(

Jonathan Alvord
03-31-2020, 05:52 PM
The only pin that had to be moved (so far) was the power pin which was pin 6 for the digitrak, and moved to Pin 19 for the Aerocruze (which was previously empty on Digitrak).