@Jochen_Trappe - Please read.
(Tested using Cubase 12.0.20)
The callback function mOnDisplayValueChange is called properly when the pan parameter is changed in the mixer GUI, but is not called at all when the volume fader is changed in the mixer GUI. (It is also not called when the equalizer parameters are changed in the GUI - those are the only parameters that I have checked). I have seen this same behavior on a script someone else wrote as well (i.e. it’s not just me)
I wrote a test script for the Mackie C4 to demonstrate.
- On the Mackie C4 I set the pan to right and the volume to -oo as shown in the following picture:
- The channel in the mixer matches these settings as shown below:
- In the cubase mixer GUI, I changed the pan to left and moved the volume all the way up to 6.02 as shown:
- Below is the response to the mOnDisplayValueChange on the Mackie C4 - Notice that the knob LEDs are correct for both pan and volume as these are driven on mOnProcessChange. The pan text (L) is correct, but volume is still displaying -oo as it never received the callback from mOnDisplayValueChange:
- Now if I nudge the Mackie C4 knob one click, the text updates to the proper value as shown below:
Please let me know if you need more information