Graupner GR24 Connection via SUMD

Allegedly it should be possible to connect the receiver via SUMD:

I’ve tried all settings.
(output8 of the receiver)

I only get a connection via PPM SUM0.
There, however, only 8 channels.

what am I doing wrong?

Andruplane 3.3.0
TX and RX FW the latest.

where did you connect the SUMD signal ?

In the tutorial is written, one should use the DSM port at the Pixhawk.
I use the output 8 at the receiver.

I’ve been digging into the code for this, and it appears to be in lib/rc , which is only referenced in modules/px4iofirmware , and doesn’t seem to be part of the HAL now.

I did get the hott_telemetry driver to work on Serial 4 (/dev/ttyS6) with a GR-24L, but the MZ-24 doesn’t show much data from it.