Symmetricom SSU-2000e User Manual page 178

Chapter 7 Input Module Reference Data
1-Port and 3-Port DS1 Input Modules
LOS Phase Considerations
Phase reading not valid when in episode
Zero phase reading when episode ends
If signal returns before the port goes into episode, normalize subsequent phase
measurements to show continuous phase numbers before and after the loss of
signal.
Others
Phase reading valid
Hierarchy of Signal Faults
The following alarms are listed in the order of most to least severe:
LOS
AIS
OOF
BPV/CRC
The Input module does not report alarms below the level of an active alarm.
Cesium Fault
Facilitates compatibility with older Hewlett Packard units
Only valid if port one is configured to receive an unframed input signal
User can select high or low logic level as alarmed
If the hardware indicates that the cesium fault level matches the alarmed setting,
log an AIS alarm against port 1.
Clear the alarm when the hardware's cesium fault level no longer matches the
alarmed level.
Input Measurement Problems
If the MTIE values for a selected clock exceed either of the MTIE masks, the Input
module takes appropriate action according to the severity level associated with the
MTIE alarms. If a received SSM has a lower PQL than the provisioned value
assigned to the port and the port has SSMs enabled, the Input module performs the
action required by the alarm mode. The action depends on the alarm mode set by
the user or the default settings. Refer to the Alarm command in the SSU-2000e
Technical Reference for more information on alarm settings.
178 SSU-2000e User's Guide 12713140-002-2 Revision E – October 2006