Meridian RS232 control question

Total newbie here and would appreciate any input.
I am seeking a solution to use the following devices which I have obtained

  1. Rasberry Pi4
  2. Allo Digione Hat.
  3. USB to RS232 cable
    I would like to know if it is possible to control(input and volume) a pair of Meridian DSP33 active speakers via RS232. The Meridian Protocol>>>