General update:
We have found that the problem is effectively 2 part.
1) When building and downloading (tried with multiple PC's) we often get a hard WDT (red LEDs on the cards) at the start of the download stage and must power cycle the PMAC.
2) When we have the PMAC running and receiving commands form our high level controller we occasionally drop the ethernet connection (lights on the cards remain green, and all plc's continue running). A soft reset might recover this, however we have no choice but to power cycle the PMAC.
