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Looking at this UT100 series communications manual, specifically pages 10 & 16, I think you're confusing:
configuration settings (baud rate, stop bit, etc.) with the command/packet, which you'll build and send with your control strategy created using PAC Control.
You can set & save your module's baud rate, etc., using PAC Manager under Tools > Inspect > Communications > Serial Modules, select your Serial Module number there from the drop-down (I'm showing module 7 here), and configure as needed:
Then save that config also in PAC Manager under Inspect > Status Write, choose "Store configuration to flash" and click "Send Command."
Then you'll use a communication handle variable in your PAC Control strategy to build that command (starting with the 2). Check out this post on Comm Handles 101.
When you build your string, if you're using OptoScript it might look something like this:
sCommand = chr(2) + chr(nUT150Address) + chr(1) + chr(0) + chr(nThisCommand) + ....
Or if you're using regular instruction blocks, you'd use the Append Character to String command:
Looks like you'll also need the built-in Generate Checksum on String command as you finish building your command/packet.
I hope that helps!