Thanks guys. Those are the best explanations yet.
The reason I was asking is that it's easy to interpret the FCOM in a way that leads you to think the CPC monitors the cabin
differential pressure even when on the selected flight altitude. But as ImbracableCrunk noted, it seems to try to maintain a constant cabin pressure once it reaches the selected FLT ALT (within 0.25 psi).
Pilots tend to answer "why"-questions with a statement of the obvious. Ofte n you get a procedure or the FCOM-text. It's refreshing to get a good "because"-answer.
So thanks ImbraceableCrunk
