Filter
Top Products
Appendix B. Understanding TR-08
B-2
TSU 120 User Manual 612020129L1-1
Table B-1 explains what conditions trigger alarms and how alarms are
processed when received by the TSU 120.
Table B-1.
Alarm Conditions
Name Explanation
FELP When the TSU 120 receives a FELP alarm, it will loop
the incoming data directly to the outgoing data. LINE
ON is placed in history. The alarms and loopback are
cleared when FELP is no longer received.
Loss of Data The TSU 120 will send MINOR ALARM and the A
SHELF ALARM for 2.5s when it quits receiving the
data link on the T-Span. It will also report TR-08 DL
Down in the history. After 2.5s, MAJOR ALARM, A
SHELF ALARM are sent across the Data Link.
OOF The TSU will send MINOR ALARM and A SHELF
ALARM upon receiving an out-of-frame condition.
TR-08 DL Down and RED ALARM are declared in
history for severe framing errors. After 2.5s, MAJOR
ALARM, A SHELF ALARM are sent across the Data
Link.
Loss of Signal The TSU 120 will send MINOR ALARM and the A
SHELF ALARM for 2.5s when it quits receiving a
signal from the far end. It will also report TR-08 DL
Down and LOS in the history. After 2.5s, MAJOR
ALARM, A SHELF ALARM are sent across the Data
Link, and RED ALARM is declared in history.
BPVs BPVs that are received at a rate greater than the
threshold set under TR-08 options, will cause
MINOR ALARM and A SHELF ALARM to be sent
on the DL. If the BPVs remain above the threshold for
2.5s, the TSU 120 will send MAJOR ALARM on the
DL. No events are placed in history.
Protection
Line Switch
The TSU will not respond to this alarm.