Dynon rx and tx with vp-x
 

Im getting tx incrmenting but not the rx....



I have an issue i am hoping to get some feedback or a little help on.

I have a dynon 7" sv hooked to a vp-x sport. I am having an issue getting them to communicate. Specifically the tx rx function.

There are 5 sets of serial wires each with a tx and rx. The tx from one device hooks to the rx of the other device, pretty simple. I have dedicate the serial set 1 to the vp-x skipped sets 2 & 3 for now and used 4 for the xsponder and 5 for the gps.

In the dynon local display setup screen i have assigned the serial ports as outlined above. The gps is incrementing on the rx line and establishes a fix. The transponder (no antenna hooked up yet) is incrementing the tx line only, nothing on the rx. Im not sure if thats normal without an antenna, but most troubling is the vp-x. Using serial wire set "1" with tx hooked to rx and rx to tx. The setup page for the vpx serial connection only shows tx incrementing. Rx stays at zero.

I figured i had made a mistake and wired them up tx to tx and verified the wiring, ports and double checked both manuals as well as checking the ground and found it to be correct. I removed the wires from the connecters and reinserted them verifying they were seated correctly.

I contacted Vertical Power and they suggested i "ring out my wiring". So i repeated all of the above verifications again with the same results.

I thought that maybe it was that set of serial lines for whatever reason so i wired up the tx and rx for serial lines "2" and of course verified that all the pins were right and tx was to rx and so on with exactly the same results.

At this point im pretty sure that either the Dynon or vpx hardware or software may be the issue. Im very willing to try anything that can be tried to identify the exact issue.

All updates and lic keys have been applied with exception to the Dynon 5.0 release. In the network auto-detect feature all attached modules have been found with the exception of the servos. The servos have to be powered to be updated and found on the network but are wired to receive power and be switched through the vpx.

I had considered that maybe i was having issue getting any/all devices to increment on the rx side but the gps on serial set "5" is incrementing and providing a fix on the map. So far everything works as it should with the exception of the communication between the Dynon and vpx (huge part of the total picture) evidenced by the big red x over the vpx page on the engine page and the lack of incrementation on the rx side of the serial lines.

Any help from Dynon, Vertical Power or the VAF member base os appreciated greatly.

Do you have one or two SkyView screens in the plane?

The simplest thing to do is hook one of the TX wires to the RX wire on the SkyView. This creates a "loopback." Set up this port as VP-X or Transponder. If the SkyView is transmitting, then the RX counter should increase. If something is broken, then the RX will not.

The transponder should increase without an antenna, but only if it has power, and I assume you have that on the VP-X too. But can't you turn on the servos and the transponder with your switches for the VP-X?

Thanks for rhe reply.
I have just one 7"skyview. I didnt think about the transponder being powered through the vpx. I do not have any of the physical switches hooked up as tbey are aveo rockrack and on backorder until feb 1st. I have hooked up an infinity grip with the ap disconnect, elevator trim, boost pump and starter and have loaded my configuration from the vpx configurator onto the vpx. I was hoping to get thing going using the soft switch function of the vpx through the dynon.

Im afraid that i have tried what you suggest above with serial TX wires from the vpx to the RX wire on the SkyView for both of the rx sides of the serial sets 1 & 2 with the same results.

Unfortunatly the airplane is 100miles away and i have to fly to it on weekends to work on it. Trying a different set of serial wires and verifying the correct wires and ports is what i did last weekend, the weekend after firing it up amd finding the issue. This weekend i would like to have a new course of action. It seems as hard as i want it to a simple wiring mistake that as you said something is broken. With whats described can you make a determination on if it would be the dynon or the vpx? Or what i could do to differentiate which pne is at fault?

Thans again,
Jesse

EDIT: i just reread what you suggested and i misunderstood that you are saying to hook the rx and tx wires from the dyon only together (loopback) and checking for incrementing on both sides after setting it up as vpx in the setup. Good deal, thanks. Should i try all 5 sets to verify, i guess i might as well?

Based on the hardware inside, if you try port 1 and then port 3 or 4 you are testing different paths inside the box.

Don't run the transponder without an antenna or dummy load!

Ok, ill hook an antenna to it for future tests.
Why is that? And what could be used as a dummy load?

Ok. Pretty unlikely that more than one "path" would have issues but as easy as you say it is to test by connecting the tx and rx lines of each serial pair from the dynon together, i may as well test all 5 pairs. Why not?

If i get the tx and rx lines each to increment and even verify that all 5 pairs are as well than its safe to say its the vpx? Or still my wiring/harnesses...

Thanks!

Our transponder is smarter than that and will not be damaged without an antenna.

On the VP-X side, you can turn on and off circuits from within the Configurator app when it's connected to the VP-X, and you also can see the TX/RX status in the system status page. Since switch assignments are easily changed around in Configurator, you can also assign a few of your stick switches to temporarily control the devices you are testing (until your regular panel switches arrive). These systems integration issues can feel difficult when you encounter them, but we have many Skyview/VP-X installations working without a hitch, usually from the first time they're connected together, so it's safe to assume (but not guaranteed) that the problem will turn out to be wiring (with configuration or hardware failure possible but rare alternatives).

--
Stephen

I guess I am still from old school, where if you run the transmitter without and antenna you will definitely do damage. It's good that the new equipment has protection. I stand corrected, at least with the Dynon xponder.

Good points Bill,
The new mode S xpdrs with ES transmit even without being interogated, I know at least some xpdrs can be damaged without an antenna or dummy load connected. I will not operate any of the ES xpdrs without a antenna or load installed (warranty may not cover this if the unit is damaged). Transmitting into an open will/can damage many transmitters and is not a good practice regardless.