Table of Contents
Advertisement
SC800 T3 Operation
Alarm Definitions
Note
The controller will display DTE alarms and Unsolicited Test alarm when a DTE (HSSI) test is initiated.
Note
The Receive Data No Transitions alarm is not operable for the subrate SC 800T3 devices which are at
firmware version 02.00.00 or greater. This alarm is only operable for the full rate SC 800 T3 devices which
are below that firmware version.
Network Alarms Definitions
Loss Of Signal
A Loss of Signal (LOS) alarm event occurs when the DSU senses an absence of incoming signal at
the interface. Absence of signal for a time equivalent to 175 bits (± 75) is considered no signal. A
Network LOS alarm, caused by signal loss at the network interface, also turns off the front Network
(NTWK) indicator.
Out Of Frame
An Out Of Frame (OOF) alarm event occurs when the DSU misses two out of four framing bits in
an incoming T3 signal, a condition that results in loss of synchronization with the signal. A Network
OOF alarm, caused by framing loss at the network interface, also turns off the front Network
(NTWK) indicator. The count for an OOF alarm increments by one each time framing is lost,
regardless of the number of frames affected.
Alarm Indication Signal
An Alarm Indication Signal (AIS) alarm event occurs when the DSU receives an AIS. A Network
AIS alarm, caused by reception of AIS at the network interface, also turns off the front Network
(NTWK) indicator.
Remote Not Responding
The Remote Not Responding alarm event occurs when the SCM, having sent a network
management command to a remote, times out waiting for a response from the remote.
Remote Alarm Indication
For C-Bit Parity, the Remote Alarm Indication (RAI) alarm is declared as soon as any of four alarm
signals are detected in the far-end alarm channel: Equipment Failure, LOS, LOF, or AIS.
For M23, the RAI alarm is declared when the far-end SEF/AIS defect persists for 2.5 +/- 0.5
seconds, and is cleared when the far-end SEF/AIS is absent for 10.0 +/- 0.5 seconds.
076R160-000
Issue 4
SpectraComm 800 T3 Data Service Unit
Installation and Operation Manual
SC800 T3 Configuration Menu
3-13
Advertisement
Table of Contents
