I got myself a RFD900 and TXMOD for testing and would like to operate it with SBUS input and output.

The hardware is on the current software status, the configuration as shown here often.

SBUS works in principle, but in the Mission Planner deflections on different channels are displayed during radio calibration without moving any stick / switch on the transmitter …

Furthermore the SBUS failsafe flag does not work. On inquiry RFDesign confirmed me by mail that there are still problems with SBUS.

Who of you has a working SBUS setup?

I have a working SBUS setup, using RFD868x and TXMODv2
Both the RC transmitter uses SBUS to transfer data (ground unit) and the Autopilot as well (air unit)

Falisafe works fine.

Details are here: RFDesign TXMOD v2 with Yaapu telemetry script on FrSky Q7

The manufacturer confirms problems and you write there are none? How can that be?

Is the software version in your link still up to date? I like to test it … maybe you can make a screenshot of your setup (TXMOD)?

I do not know hot that can be. But I can tell you that it works here, and some other user have it working as well.

You do need to update some of the firmwares. Have you done that?
The ones I posted do work, and I tested it with ArduCopter 4.1.1

I think I have it … This is probably due to the refresh rate in the transmitter. By default 7ms are set for SBUS. I think you have taken 10ms and so it runs in the short test incl. failsafe.

Can you perhaps test once, what happens with you, if you set the refresh rate to 7ms? Then errors should also occur.

Yes, 7ms make it go a bit crazy,m I have set it to 20ms now.

I updated the original post with some more information