Another VP-X question

[Don]

Wiring has been progressing smoothly and I'm nearly ready to install the avionics stack and start testing it, but? I've got one bug I can't solve.

I using the VP-X Pro and I have hooked up and tested all of my switches. Switches 1-10 and the flap switch show the correct on and off status on both the VP-X configurator and on my HX. The flap switch shows the proper up and down when the momentary switch is activated. I have hooked up all of the lights, the pitot heat, the EIS, both EFIS's and the AHRS to power and everything comes on when its switch is flipped to on, or shows 12 volts, if it isn't hooked up.

The flaps however are vexing me. When I turn the system on, it boots up to a 'Runaway Flap' error. When I reset it on the configurator, nothing happens when I activate the switch. All of the other switches send power to the device except the flap switch and it doesn't make sense to me.

I am using a DPDT switch wired as a SPDT switch. I've tried two different switches. I've tested both switches and they seem to work correctly and like I said above, the VP-X configurator and the HX screen both show UP and DOWN when the switch is pused up and down. The flap motor works when connected directly to power. I've double checked the power leads and they are in J12 pins 5 and 6. I've checked the wires from pins 5 and 6 for shorts and found none.

I''ve gone into the confugrator and the flaps are active, set-up as a momentary switch, and I can't see much else to do. I've read the manual and I can't find any suggestions.

[KPLU-RV8]

I just happen to going thru the install manual tonight for my VP-X pro. You may try seeing if at the J2 pin 14 (Flap up) or J2 pin 15 (flap down) switch are grounding at the same time. If both up and down are grounded at the same time for over 3 seconds a flap runaway error could be shown and the flap system disabled. You may try disconnecting the wires from the switch and powering the system up. But i'm still trying to learn all the ways these VP-X's can be wired up. Good Luck

[Jackm]

Don,
Which position sensor are you using and what values are you reading on the configurator?

[Don]

Originally Posted by Jackm

Don,
Which position sensor are you using and what values are you reading on the configurator?

I am not using a position sensor (yet). I have set the configuration to momentary. As I understand it, the flaps will move when I push the switch and stop when I let up. The Ray Allen switch is optional.

If you watch Marc's demo of how to wire a VP-X system on Vimeo (https://vimeo.com/9635040) he shows how to wire the switch and the power leads. He doesn't use a position sensor. This is exactly what I did except I used the pins specified for the VP-X Pro (he uses another model).

I'm moving forward with the wiring while I wait to hear from either Marc or Astronics. In the worst case (as in I can't get this feature to work), I'll ditch this feature of the VP-X and just use it to provide circuit protection.

[Don]

Originally Posted by KPLU-RV8

You may try seeing if at the J2 pin 14 (Flap up) or J2 pin 15 (flap down) switch are grounding at the same time.

Any thoughts on how to do this measurement? The switch wiring tests good in the configuration and in the GRT HX.

[Taildrgr]

I just finished wiring my VPX per the installation instructions and it worked fine. I used the terminals on one side of Van's supplied flap switch. Connected ground to the center terminal, J2-14 and 15 to the top and bottom terminal on the same side. No jumpers on the switch, only the 3 wires. The two motor power wires go to J12-5 and 6. You can test the switch by connecting a multimeter to the airframe ground and one of the top or bottom switch terminals and you should see a short when you flip the switch one way only. If you see a short on the switch in both up and down, then the switch is bad or wired incorrectly. Hope this helps.

[Don]

Originally Posted by Taildrgr

I just finished wiring my VPX per the installation instructions and it worked fine. I used the terminals on one side of Van's supplied flap switch. Connected ground to the center terminal, J2-14 and 15 to the top and bottom terminal on the same side. No jumpers on the switch, only the 3 wires. The two motor power wires go to J12-5 and 6. You can test the switch by connecting a multimeter to the airframe ground and one of the top or bottom switch terminals and you should see a short when you flip the switch one way only. If you see a short on the switch in both up and down, then the switch is bad or wired incorrectly. Hope this helps.

Bob,

Thanks for the reply. I wired the switch exactly as you did and it passes the grounding test. I have used two DPDT wired as DPST switches (as you describe). One switch was from Vans and the other was from Stein.

This isn't difficult wiring (not that I couldn't make a mistake - but I'd quickly find it) and I'm seriously wondering if there's a problem with the flap circuit in the VP-X. I wish there was a way to determine that with some certainty.

Don

[jwyatt]

Originally Posted by Don

This isn't difficult wiring (not that I couldn't make a mistake - but I'd quickly find it) and I'm seriously wondering if there's a problem with the flap circuit in the VP-X. I wish there was a way to determine that with some certainty.

Try removing the flap switch input pins from the VP-X DB connector (J2-14/15; leave the motor pins connected), then powering up to see if you get the same error message. If you do, that would point to something internal to the box. If the error does not appear (with the switch wires disconnected), that would indicate something is amiss with the field wiring outside the VP-X box.

If the error clears with the wiring disconnected, then I'd rig up a test switch with all new wires and temporarily connect it to the VP-X, to see if it works properly.

Originally Posted by VP-X Integration Guide

A flap runaway condition is detected if both the flap up and flap down switches are engaged at the same time. If the VP-X detects this condition, the flap circuit is turned off and the flaps are faulted with the runaway fault code.

[Don]

I think I've found the problem. Pins J2, 14 and 15 appear to be shorted together internally. Here's how I discovered that.

First I checked the flap power wires for any shorts and found none. They were connected to J12, 5 and 6 as called for in the installation. Then I started testing the switch and noticed I had continuity between the flap up and down switch. The switch(es) was (were) wired correctly (I had two switches, one from Vans and one from Stein). The flap up to ground was open until the switch was activated, as was flap down. The switch pins (J2, 14/15 were not grounded) were shorted.

I then made up a test male d-sub connector with only these two pins connected and checked for continuity. There was a small amount of resistance almost but not completely shorted. I believe this is what's giving me the run away flap error - the VP-X thinks both up and down are being called for together.

Astronics has a message saying they're still transitioning to take over VP-X. I left a message and will wait to see what they want to do - or perhaps tell me I've misdiagnosed the problem. I also e-mailed them. The last time I had a problem Marc was quick to call and I'm hoping he will be this time, too.

[Bill.Peyton]

You may see some resistance when you check the resistance across the two VPX pins. Depending on the circuit design, this could be normal.
Did you try to totally disconnect the flap switch pins AT the VPX and see if you got the error? This error is generated when those pins are both connected to ground at the same time for 3 seconds. Are you absolutely sure you are on the correct VPX pins? The next step would be to disconnect the flap motor at the VPX and see if the error occurs. This would isolate the problem to the VPX or external wiring depending on the outcome.