AT&T MERLIN LEGEND Installation & Maintenance Manual page 523

Maintenance and Troubleshooting
The 100D System Module—T1
Maintenance
Every 15 minutes the system checks the 100D module for the
following:
Initialization. The system ensures that all T1 ports are properly
initialized and placed into service. It also resolves the
conflicts of different service levels (for example, between the
individual ports or for the initialization of the ports to support
features).
Error detection and handling. The system detects errors and
takes the facility out of service, if appropriate. It attempts to
restore the facility and put it back into service.
Error recording. The system records all errors and outages in
the error logs.
Audits and updates. The system checks the state of the T1
facilities through audits, status checks, and error logging.
Maintaining the synchronization plan. The system maintains
proper synchronization to the loop clock and switches to the
local clock when the loop clock is not available (for example,
during a loss of signal or a blue alarm). When the loop clock
source is restored, the system switches back to the loop
clock.
Maintenance 5-45