PJ2 and HarryMann, thanks for both the quality explanation and patience.
If I follow this right then the CPC's receive inputs from the FMGS and ADIRS. I assume the altitude information from the ADIRS is determined in part from the static tubes.
Is the system normally flown in Auto mode?
Do you know if the ACARS msg corresponds to the Max Differential Pressure Limiter Function limit being hit or Cabin V/S 1800+-fpm?
I was mainly wondering of the cabin press ACARS msg was a sign of an actual problem (breakup, rapid altitude change, etc), or if bad altitude information either from ice buildup on the tubes or anomalous ADIRS info could have convinced the CPC that the A/C altitude had changed significantly beyond an amount it could compensate for, triggering the warnings and ACARS msg.
Also are the two pneumatic safety valves completely mechanical in nature? Everytime I turn around I run into another computer, so I thought it best to ask.