Sorry, I don't mean to hijack the thread. But you have me thinking the right order of things.
I guess the difference is, that I want to pulse the hand controller - simple enough through an optocoupler.
I think it would work this way. The Linux box running CdC set to a generic encoder setup will receive position information from the mounts shaft encoders, which is translated to serial output and fed the Arduino which schedules the hand controller and activates the motor, and so on...
The difficulty for me is the serial interface with the Arduino. Is it just a matter of knowing the pin out for the serial connector and hooking the output to the Arduino pins as INPUT? I think it would need 2x RA and 2x DEC outputs - one for each button. I guess so