[evlatests] New L350

[Jim Jackson]

A new L350 Central Reference Generator module was installed in the 
EVLA system on Wednesday.  This module now contains the hardware and 
firmware to replace the IAT clock.  The correlator 0.1PPS and L8 
reset reset signals formerly supplied by the IAT clock are now coming 
from the L350.  Hopefully this will greatly reduce the possibility of 
another undetected timing synchronization problem like occurred 
earlier this month.

In the next week or two we plan to add Slot ID to this module but 
currently it is accessible in the device browser as 
"EVLA-MIB-0-7D"  The critical monitor points are:  PLL_LOCK_DETECT, 
EVLA_SYNC_DETECT, and VLA_SYNC_DETECT.   The value of these three 
monitor points should be "1".  If any of them are solidly "0" the 
system is broken.  At the moment , the sync detects will occasionally 
glitch to "0" for a few seconds then return to "1".  This can be 
disregarded - it is believed to be a fault in the monitor logic and 
is being looked into.

Jim Jackson