System Monitor Indicators; Nt8D22 System Monitor - Nortel Meridian 1 General Maintenance Information

System monitor indicators

NT8D22 System Monitor

The system monitor checks the column temperature, cooling system status,
and system voltage status and controls line transfer states accordingly.
System Options 51, 61C, 81, and 81C are equipped with the NT8D22 System
Monitor, which is installed in the rear of the pedestal in each column. Table 5
lists faults monitored by this system monitor.
Note: In multiple-column systems, there is one master system monitor,
located in the column with CPU 0, and multiple slave system monitors.
A switch setting on each system monitor defines the master or the
address of each slave.
Table 5
Faults monitored by the NT8D22 System Monitor
Power faults
CPU condition
Main power loss
Power supply failure
Temperature alarm
The master system monitor checks the CPU column and periodically polls the
slaves to check their status. When polled, the slaves report their status to the
master. If a slave does not respond when it is polled, the master reports the
address as a faulty slave.
Hardware maintenance tools
Source
CPU failure
Sysload (system reload)
System input power, AC or DC
Common equipment power supply
Common/peripheral equipment power
supply
Peripheral equipment power supply
Ringing generator
Blower unit
Column temperature sensors
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