Nortel DMS-100 Series Maintenance Manual page 111

configuration provides a redundancy of power from both power feed sources
to each unit of the Star Hub. There is also some redundancy. When the talk
battery returns, a single fault may not cause an outage.
If a talk battery fuse blows, the Star Hub indicates InSv (in service) at the
MAP display. The Star Hub performs a line card audit, but this audit cannot
check for loss of a talk battery. The loss of a talk battery may have an effect
on one unit of the Star Hub, depending on where the fault occurs.
Without a talk battery, the Star Hub line cards cannot signal an off-hook
condition. Thus, the Star Hub detects any off-hook line as being on hook. The
system automatically forces any Star Hub calls to the on-hook state when the
Star Hub loses talk battery feed. The Star Hub lines cannot originate and
terminate calls while talk battery is not available.
Talk battery alarm activation
To activate the Talk Battery Alarm feature, change the value of office
parameter TALK_BATTERY_ALARM in table OFCENG. (The system
disables the Talk Battery Alarm feature by default.)
When the Talk Battery Alarm feature is enabled, the system performs talk
battery testing through diagnostic programs and audits that run as background
processes.
If the Talk Battery Alarm feature is disabled, the system automatically clears
any talk battery alarms and ISTb reasons introduced by this feature.
Background process audit
The Star Hub can test its shelves for loss of talk battery. When the Talk Battery
Alarm feature is disabled, no audits are run to check for the loss of talk battery
on any of the LCMs or Star Hubs in the office.
When the audit finds a failure the talk battery test, a critical alarm log report
(PM179) is output and places the LCM shelf in an ISTb state. The audit does
not report the failure until diagnostic programs clear the alarm and ISTb state.
Diagnostic programs
The InSv and OOS diagnostic programs include the talk battery test for a Star
Hub unit. The following commands include the diagnostic programs:
• TST Unit unit_no
• TST PM
• TST REX NOW
• RTS Unit unit_no
• RTS PM
Star Remote System automatic maintenance 4-11
DMS-100 Family NA100 Star Remote System XPM15 and up