I don't know about Ofelia, but you should be able to install a workarround with a screengrabber software. E.g. with OBS studio you it should be possible to grab the ofelia window and bring it to the second screen. Maybe not the best quality solution, but i have used such workarounds where quick and dirty was needed.

Dear @jameslo and @whale-av! Thank you for looking into this. David you really did dig into this, thanks! I finaly had to finish the show without this raspi controller because i could not get it to work, and now i cant touch the cameras for a while. But i hope i have the chance to investigate again. Here are some answers to your questions for future reference meanwhile:
What about the serial port stuff like baud rate, start & stop bits, etc? Is that all set to what the camera expects? Do you have the right port #?
-> I really dont know. I have a similar Camera like this followed this manual for the rs422 commands and dont know what else it needs concerning start and stop bits.
The camera has to Interface for VISCA over IP unfortunatly.
Is the camera set as camera 1?
-> I think so, yes. I use this controller and it works.

• Does an error message come back from the camera?*
  -> i don't know. I dont know how to read whats coming back.
• Have you thought of doing it over IP..... ethernet?*
  -> yes that would be the best, but i think my camera does not support that.
• Does the camera have the firmware upgrade (around year 2019) that enables HEX commands?*
  -> i think it should work with HEX since the controller is working fine.
  But I wonder if a text string would in fact work........ [print 81 01 04 3F 02 01 FF( ....into comport.
  -> I will try that, even though i have not the biggest hope for succes this way.
  do you have noise from a bad ground or a bad power supply?
  -> could be. But if i evaluate my knowledge so far, i think it is most likely a user error still. I will report here if i know more, or have more questions.

@alexandros, no. I send the numbers directly allready now, like shown in the [comport] help patch. My camera is still not moving.

The device manual demands this Hex numbers:
81 01 04 3F 02 01 FF
as far as i understand now this is the list i need to send:
129 1 4 63 2 1 255
i didn't find a universal solution in your answers, but followed this table, which also shows the bits and therefore i beginn to understand a little bit more..

well, @whale-av, @alexandros, i thought that the conversion of [list fromsymbol] is what i need 'cause with print i get the bytes to send? I only understand half, so is it for you possible to follow what i mean:

[FF(
|
[list]
|
[list fromsymbol]

{bundle bytes and send to device}

puuh, thank you all, i will try to see through all of this. The system is very hard to debug for, 'cause the Camera is either moving or not. And there are a few stepping stones on the way..

I am trying to controll a Marshall PZT Camera with a raspi over rs422 over VISCA protocol. I think i can use [comport] but i don't understand puredata (anymore).
In the camera manual it tells me to send a string of HEX numbers 8x 01 04 3F 02 01 FF but with comport i can send bytes as decimal numbers. I dont understand how to convert these.
Does anyone has experience or understands how to do this?

I didn't test anything, but pix crop comes into my mind...

Yes, i remember that problem from quite a while back. Cant remember the solution though. Try playing with the auto message. Or maybe it worked with [open however/name 2( message to change backend? I came back to check when i am at my computer..

@svanya nice track!