Does dbx have a list of RS-232 strings for controlling the ZonePRO products via a 3rd party controller?
No, there is no list containing all of these strings. This is because the strings will change based on how the ZonePRO is programmed. You will need to use the ZonePRO String Calculator to generate the strings for your controller. You can find this ZonePRO String Calculator and the RS-232 Protocol Guide at the below link.