Appendix B. Understanding TR-08B-2 TSU 600 User Manual 61202076L1-1The following table explains what conditions trigger alarms and howalarms are processed when received by the TSU 600.Table B-1. Alarm ConditionsName ExplanationFELP When the TSU 600 receives a FELP alarm, it will loopthe incoming data directly to the outgoing data. LINEON is placed in history. The alarms and loopback arecleared when FELP is no longer received.Loss of Data The TSU 600 will send MINOR ALARM and the ASHELF ALARM for 2.5s when it quits receiving thedata link on the T-Span. It will also report TR-08 DLDown in the history. After 2.5s, MAJOR ALARM, ASHELF ALARM are sent across the Data Link.OOF The TSU will send MINOR ALARM and A SHELFALARM upon receiving an out-of-frame condition.TR-08 DL Down and RED ALARM are declared inhistory for severe framing errors. After 2.5s, MAJORALARM, A SHELF ALARM are sent across the DataLink.Loss of Signal The TSU 600 will send MINOR ALARM and the ASHELF ALARM for 2.5s when it quits receiving asignal from the far end. It will also report TR-08 DLDown and LOS in the history. After 2.5s, MAJORALARM, A SHELF ALARM are sent across the DataLink, and RED ALARM is declared in history.BPVs BPVs that are received at a rate greater than thethreshold set under TR-08 options, will causeMINOR ALARM and A SHELF ALARM to be senton the DL. If the BPVs remain above the threshold for2.5s, the TSU 600 will send MAJOR ALARM and onthe DL. No events are placed in history.ProtectionLine SwitchThe TSU will not respond to this alarm.
