ADTRAN 25 manual General Maintenance Information, System Errors and Alarms, Emergency Transfer

MAINTENANCE

GENERAL MAINTENANCE INFORMATION

System Errors and Alarms

During periodic testing, a maintenance audit could detect a system error that automatically generates an error record. Depending on severity, the error record is stored in one of following three tables in the Error Log:

●Permanent System Alarms

●Transient System Errors

●Most Recent System Errors.

The three error tables can be displayed at the System Administration Terminal (SAT). The error tables are used to diagnose and analyze problems, particularly when the problem has not caused an alarm or when alarms cannot be retired by replacing faulty units.

The errors are listed in the error tables by time of occurrence. Resolved and unresolved errors are listed, thus providing a profile of the past and current state of the system. Error message explanations are provided under “Error Messages” in this section.

Emergency Transfer

System 25 has emergency transfer capability in case of total system outage. The Emergency Transfer Unit (ETU) connects preassigned single-line voice terminals directly to the CO, bypassing the System 25. Emergency transfer is invoked by loss of ac power or by any failure of the system that prevents it from processing calls.

Circuit Pack LEDs

During the various states of operation (start-up testing, normal operation, and failure), CP LEDs appear as follows:

Note: The first two listings, Memory and Call Processor, apply only to Release 1. The CPU/Memory circuit pack applies to Release 2 and Release 3.