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Fence is unavailable to write to pixhawk 2 when use 915MHz data transfer on QGC

When I use 915MHz to write fence to pixhawk on QGC, get error. But if use USB cable, it works. I have to link a USB cable to test rover follow rover running.
When switch to 915MHz transfer/receiver, the fence feature is gone. It looks the fence is not written to pixhawk 2.
How it works fence feature on QGC using 915MHz transfer/receiver.

My guess would be that you radios are using older firmware which does not support Mavlink V2 protocol. Fence/Rally requires Mav 2 protocol. Also make sure you are using Daily builds since there are many fence/rally fixes in there. You need to flash your radios with latest firmware.

… also maybe try setting the appropriate SERIALx_PROTOCOL = 2 (for MAVLink2) where “x” is the serial port number. so for example, if the radio is connected to “Telem1” then modify the SERIAL1_PROTOCOL.

Thanks for the report!

We tried Mavlink 2, it is same issue.

ok, it’s probably what Don says, the radio itself doesn’t support mavlink2.

Also I have found cases where I had to once connect to the vehicle using mission planner and then after that if I connected with QGC, the fence feature worked.

yes, I tried same thing, draw the fence in QGC, then back to mission plan using radio. some time works, most time does not.


If this is a SiK radio could you try updating the firmware on it? It should be possible to check if it’s a SiK radio by pressing the “Load Settings” button on the page below (if it connects and displays values in the various fields then it’s a SiK radio). Note that you may need to set the COM port drop-down, baud rate and it may even be necessary to check that the “connect” button is in the disconnected state. Sorry for the slight unclear details, I haven’t updated the firmware myself on too many radios.

I will try it, thanks a lot.

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If you run latest QGC daily builds and turn on VehicleLog ( it should tell you what is going on with respect to vehicle capabilities and mavlink 2 protocol negotation. Older daily builds have similar logging, but there is more information in latest dailies.

Servers by jDrones