After years of service, my DP832 gave up a ghost. The processor board won't boot any more. I checked the voltages and tried to isolate the problem with no success. There's not much else I can check or replace on that board so I think I'll just let this one go.
Although... the two analog boards seem to be fine. A quick look around revealed communication is done using isolated UART at 115200 with another 2 isolated signals (output enable maybe?). I haven't done any more of RE in hopes that someone else can't keep their logic analyzer to themselves.
So! Has anyone reverse engineered the protocol used to control those boards? Or at least captured some packets.