It was determined late yesterday that while it appeared that everything was functioning on h0velx, in fact the control of the solenoid that allow LN2 into CP2 was not actually functional even though the readback on the MEDM implied that it was.  I spent most of today tracking down where the problem lies.  Recall that we had to replace the 2210 card that was originally installed due to a fail light that would not clear on reboot.  We verified that there was a lack of 24V signal at the solenoid first.  I then traced the cabling through the VE rack and was able to determine the 24V supply was present at the input of the FLKM for the 2210 card, but not present on the output regardless of the software setting on the crate.  Further verified that the operation of the relay can be heard on the 2210 card as the software switch is toggled.  Then tried swapping out the relay on the card to rule it out as defective with the same results.  Swapped the card entirely with the remaining spare, also with the same results.  It seems highly unlikely that the same relay on two boards is bad, even after swapping with another (assuming I chose the correct socket/relay).  At this point I suspect a cable issue between the 2210 card and the FLKM terminal block, but have been unable to find a replacement cable ready made on site.  To get the system working, I have bypassed the 2210 card, and wired the 24V supply through to the watchdog card, which then supplies the solenoid.

Original signal path:

24V Supply -> 2210 Relay Control Board -> VME Bus Watchdog Board -> XV150 (CP2 LN2 Fill Solenoid)

As wired now:

24V Supply -> VME Bus Watchdog Board -> XV150 (CP2 LN2 Fill Solenoid)

The VME Watchdog board will (presubably) close the control valve if it VME crate locks up/reboots, providing some of the same level of control as before.  However:

The MEDM software fill valve request control WILL NOT FUNCTION IN THIS STATE.  The readback (HVE-LX:CP2_XV150INT) will change if the switch is toggled, but it is no longer physically wired this way and the state of the MEDM has no bearing on the actual state of the valve.  TO DISABLE THE VALVE: you must pull the appropriate fuse block in the VE LX rack that feeds the field cable marked 'XV150'.