Some work on failure detection and CWS messaging.
The way this operates in the Shuttle is as follows:
If there is a problem detected which isn't an emergency (which has its own independent alarm system), then a flashing line appears at the bottom of every DPS screen. In this case I get a R OMS QTY indicating that my OMS fuel is dropping below 5% for some reason. Acknowledging the message stops the flashing, and doing it again brings up the next from the stack (if there are more).
Inspection of the fault summary page reveals the last 15 fault messages with their timestamps and shows a few RCS-related problems as well:
The GNC systems summary page shows that RCS manifolds 3 and 5 have issues (have experienced a 'fail off' condition) and the manifold isolation valves have been closed to prevent any leakage.
It's a neat system, though tedious to code...