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Taranis as Slave with Dx5e as Master - Servo twitching and Throttle goes up and down

Posted: Wed May 11, 2016 10:36 pm
by rguptaca
See video.
https://youtu.be/qAxRKkfjBKg
Servo twitching and throttle up then down every 6 to 30 seconds.
Dx5e as master.
Spektrum trainer cable (the official expensive mono to mono cable).
Apprentice S 15e Rx.
FrSky Taranis Plus Tx as the slave.
OpenTx 2.1.8 2016-04-14 EEPR 217
PPM Frame default settings of 22.5ms 300u -

I also tried using a Taranis (not plus) with the same problem.
OpenTx 2.1.3 2015-10-01 EEPR 217
I used default values.
Channel values on Taranis are stable when viewed using the channel monitor.

I also tried different cables.

I am able to control the plane servos with the Dx5e when the Trainer switch is Down; Instructor has control.
I am able to control the plane servos with the Taranis when the Trainer switch on the Dx5e is Up (student has control) but there is servo twitching and the motor starts and stops on its own.

We have been using this setup where the Dx5e is the master and a variety of Spektrum transmitters as the slave with no problems.
We only have this problem when trying to use the Taranis as a slave to the the Dx5e.

As far as using a stereo cable goes the Taranis has the ground and middle/second conductor shorted (I checked with a multimeter) so signalling on the electrical/physical layer is probably not be the problem.

When the Taranis is the master and I use any Spektrum transmitter as the slave the system works without problems.

Re: Taranis as Slave with Dx5e as Master - Servo twitching and Throttle goes up and down

Posted: Wed May 11, 2016 11:08 pm
by jhsa
rguptaca wrote:S
PPM Frame default settings of 22.5ms 300u -
Try changing this to 400uS
See if it helps ;)

João

Re: Taranis as Slave with Dx5e as Master - Servo twitching and Throttle goes up and down

Posted: Thu May 12, 2016 12:53 am
by rguptaca
@jhsa
Based on your response and this thread http://www.rcgroups.com/forums/showthread.php?t=2416188
I changed
PPM Frame to 22.0 ms 400u -
I also changed OUTPUTS so that the min max ranged from 1100 - 1900 ms with centre on 1500 ms (I had it at 1520 ms).

Works.
Thanks.

Re: Taranis as Slave with Dx5e as Master - Servo twitching and Throttle goes up and down

Posted: Thu May 12, 2016 1:12 am
by jhsa
well done ;) :D

João