Rich, there are a number of steps that you will have to go through regardless of the make of radio (transmitter). Mine is a Hitec Aurora 9 but I'm pretty sure the set-up isn't any different...
1) Plug the WK-M into your PC via the USB lead and spark up the DJI Wookong application. Select the Tx Cali page.
2) Turn on your transmitter and operate the 3-position switch that you use when selecting 'GPS', 'Attitude' or 'Manual' mode. You should see the blue indicator move along the Control Mode Switch U slider to the relevant position...ie... GPS for switch position 1, Attitude for switch position 2 and Manual for switch position3.
3) With the transmitter fail-safe setup in mind set the fail-safe throttle position to a minimum of around 10% and then reset the transitter End Point Adjustment (EPA) so the the Control Mode Switch U slider goes to 'Fail-safe' for each of the switches 3 positions.
4) Now go through the Transmitter/Receiver Fail-safe setup routine for the DX8. My Hitec does this in a 5-6 seconds window so ensuring that all is in place is paramount.
5) When complete power off the receiver and then the transmitter.
5) Power everything on again as per normal and reset the EPA settings for your 3-position switch back to 'GPS', Attitude' and Manual.
6) Prove that it all works as designed and planned by placing the 3-position switch in 'GPS' mode and then power off the transmitter...the Control Mode Switch U slider blue highlight should move from 'GPS' to 'Fail-Safe'. This should be the same for 'Attitude' and 'Manual' modet switch positions.
I apologise if this all sounds a bit lengthy and tedious but if things go wrong for your craft up in the air it will pay dividends.
6)prAll
cneradio...d