This evening I added a second ADC module to the prototype Acromag chassis. This chassis can now read out all the PSL diagnostic channels.
I configured the second ADC identically to the first ("ADC0"), and assigned it IP address 192.168.113.122. I confirmed it is visible on the martian network.
There was an existing but unused DB-15 feedthrough which I used for ADC1 channels 1-7. The eighth channel I left unwired, but there are slots available in the neighboring DB-25 feedthough, if that channel is needed in the future. The channel wiring assignments are as follows.
I tested all seven of these channels by applying a calibrated voltage source and measuring the response via the Windows Acromag software. All work and are correctly calibrated to better than 0.1%.