Ch1, Ch2, Ch3, Ch4: (THR, AIL, ELE, RUD): Normal default mixes, but different order than FrSky default. Be sure you're set the input properly for each channel.
Ch5: AS3X/SAFE: Set to any 3-position switch you like.
Ch6: Emergency: Bind to momentary switch. SAFE Panic Button when switch is pulled.
Outputs Screen
- All Channels: Set limits, Min=-77.7, Max=77.7.
This compensates for fact that OpenTx 100% = Spektrum 80%. - Ch2, Ch4 (AIL, RUD): Set Direction=INV to reverse inputs.
Set throttle range by usual procedure: Power on radio, throttle stick max, power on plane, after beep lower throttle stick to min.
Tech note:
https://www.spektrumrc.com/ProdInfo/Files/Remote%20Receiver%20Interfacing%20Rev%20A.pdf
At ±100% travel, the data range is equivalent to a “Servo Position” data range of approximately 341 to 1707 which translated to PWM equals 1102µs to 1898 µs.
Note: Limits and channel order don't apply if you have a DIY-Multimodule, which performs these translations automatically. use AETR channel order and 100% limits.
https://github.com/pascallanger/DIY-Multiprotocol-TX-Module/blob/master/Protocols_Details.md#DSM---6