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trackdom

Well Known Member
Hi,
I am hardly trying to connect my VPX to the Grt sport EFIS . I Used serial ports from VPX ( J1-20 J1-22 ) connected to pin 33 and 37 of EFIS .
But I don't know where I Could connect J1-21 serial ground in the EFIS.
The main issue is I can't get the elevator and roll trim on my EFIS.
I got the 2 bars and a little triangle but the the triangle doesn't moves when I trim...
Thanks
 
I have my VPX connected to an AFS EFIS, so my pinouts would be different. But I don't believe you would need the serial ground. Do the other functions work (viewing and turning on/off electrical loads)? If so, then I would say no ground is needed.

(For the AFS EFIS there is 1 serial port with a ground and 2 other ports share a ground, and the other ports don't have a ground. I do have my VPX connected to a port with a ground.)

I would think maybe the trim servo wires are not connected to the VPX correctly. If you connect your computer to the VPX can you see the trim encoders counting?
(maybe a dumb question: Do the trim motors move?)

here is my roll and pitch pinouts for the VPX:

pin J1-
1 Fuel sender Left
2 Fuel sender Right
3 roll trim +2.5v white/blue - black
4 roll trim ground white/orange - red
5 roll trim position input white/green - white
6 roll trim motor power
7 roll trim motor power
8 Pitch trim +2.5V white/blue - black
9 Pitch trim ground white/orange - red
10 pitch trim position input white/green - white
11 pitch trim motor power
12 pitch trim motor power
 
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Hi Jcaplins,
In fact it's strange...as all is working perfectly except trim positionning doesn't move . I checked all the connexions from servos to VPX, 5 wires , it's ok . Servos motors work when trimming , on the screen I can see counter receiving from VPX , I can see electrical scheme from VPX , green lights when trimming ....So vpx communicates with EFIS. Among the EFIS connexions I don't see any ground serial. I connected Tx and Rx from VPX to Rx and Tx of EFIS .
Actually I am stuck with that very last bug I 'd like to solve before flying...
Thanks
 
call / email GRT...

...they are very helpful. I have always received prompt and accurate support from them.
 
Hmmm...
Since I don't have a GRT, I can't be of much more help.
Do you have more than one GRT screen?
I belive the GRT EFIS was originally intended to get it's trip position data from the GRT EIS. Since you are getting the data from the VPX, maybe there is a software setting in the EFIS? Perhaps it's looking for the trim indicators to be directly wired to the EFIS instead of from the VPX?



I do have a VPX, and this is from the manual:

5.12 GRT EFIS Wiring
On the HORIZON, trim and flap position are shared on the display
interlink between display, but the status of each electrical device is not.
The VP-X electrical page only appears on the display that is wired to the
VP-X. On the SPORT, no data is shared between the displays, so wire
the VP-X serial line to the display on which you want to see trim and flap
position and VP-X electrical page.
Use a serial port pair on the EFIS. Make sure the EFIS and the VP-X are
wired to the same ground. Do not use the serial ground on the VP-X.
 
Connect the configurator to the VP-X. On the trim page, look and see if the trim position number changes as you move the trim. If it does, then the trim is not configured correctly on the GRT. If it does not change a lot, then the trim position wires are mis-wired.

If you're getting all the other data on the GRT, then you don't need to wire the serial ground. All of the data is getting from the VP-X to the GRT just fine.

Hope that helps.
 
Dominique and I have been talking over email and phone...he doesn't have a computer with the configurator on it yet. Just wanted others to know that his support issue is being worked on. :cool: Should either be fixed or we'll know what to look at when his configurator is up and running.
 
Hi Chad, Hi everybody,
Feedback today...
My problem has been solved and was due to low cost connexions working bad...trim motors always worked fine but not the wires sending position to VPX and then to EFIS .
I have to thank Chad from VPX and GRT support for there kindness to help me , by phone or by mail !
 
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