First, Thanks to everyone for your suggestions and ideas.

I tried the cisco console cable and it did the trick for the DSP7200SE R & L speakers.

I tried the same on the DSP7200HCSE (using the center channel firmware), and am now getting a "Bad code" readout on the speaker's front panel.

Can anyone suggest a next step to get out of the "Bad code" scenario?

Thanks

Living room: 818v3, Audio Research D150, Maggie 1.6
A/V room: 861v8, DSP7200SE L/R/C, 4x DSP320 surrounds, ID41 + Roon, UHD722, Prime+PS