Auto-trim and Vertical Power display

[cjohngraham]

I have a VP-X Sport box, Skyview HDX, and a Ray Allen elevator trim servo. Initially I had all elevator trim wires going to VP-X and trim could be operated from both the stick grip switches and the VP touch display on the HDX. However, I learned that SV auto-trim only works if the trim motor and trim switches are wired directly to SV AP-74, which I then did. The ground, position input, and reference voltage wires from the Ray Allen cable remained wired to VP-X. If memory serves me, trim could still be operated by touch from the VP display on the HDX at that point. However, now trim no longer works by touch on the HDX. The only thing I know that's different is that I actually set up the pitch auto-trim. Does anyone know a way I can restore trim operation from the HDX's VP display? Trim position in VP-X setup is set to VP-X.

 

[Dynon]

This is a 90% answer - I'm not a VP-X expert - although I've vetted it with our engineers: In this case, you'll want to pick one or the other. Because of the way that both VP-X and SkyView's AP Panel reverse the polarity of the power to drive the motor direction, there isn't a safe way to have them both control the trim. We'd of course recommend using SkyView, as it afford autopilot auto-trim and its other safety-enhancing features. But you'll give up the on-screen trim controls. If you do choose to use the AP Panel as the trim controller, you also want to only use the VP-X as a circuit breaker for those circuits. Their manual discusses the wiring differences in that case.

 

[jakej]

DS - correct. If a customer has an Auto Pilot Panel then I use it & then I use 1 x VpX circuit to power it only. If no SV A/Pilot panel fitted then I use the VPX trim system - it's either 1 or the other but not both

 

[cjohngraham]

Thanks for the info. One more question: the SV installation manual Fig. 77 shows 3 wires for position input from Ray Allen: signal, ground, and power; the latter is called out as 5V. The VP manual shows signal, ground, and a 2.5V reference voltage. I'm assuming the reference voltage wire is the same as the 5V power wire; does the voltage difference matter? The two manuals also list different colors for the same wires, so just want to make sure. see atch.

 

[jakej]

It's one & the same - 2.5 or 5, doesn't matter.