Escalation To Manual Maintenance - Nortel DMS-100 Series Maintenance Manual

The REX test checks the ability of the Star Hub units to enter and exit ESA
mode. The REX tests also test the ability of the Star Hub unit to send messages
to the ESA software in the RCP while in ESA mode. A REX test checks one
Star Hub unit at a time. Tests of two units at one time can result in a loss of
service for connected calls. While the REX test checks one unit, the other unit
continues call processing in the takeover mode.
The system tries to prevent accidental attempts to perform maintenance on a
Star Hub unit that is in ESA mode. To prevent maintenance on a Star Hub, the
system runs a lockout task on the LCM unit that the REX tests. The lockout
task is the same task used in an ESA exit. Lockout does not perform
maintenance.
Takeover and takeback on a Star Hub unit affects calls the system starts to
connect. These processes do not affect connected calls. The Star Hub unit
returns to service before a REX test checks the other unit.
The following actions occur during a REX test:
1. A REX test checks the messaging ability of the peripherals, ESA
2. If the preliminary tests pass, one Star Hub unit goes to the SysB state and
3. The ESA software in the RCP card tests the ability of the Star Hub units
4. The system performs other diagnostics of the ESA capability including
5. After the tests are complete, the unit goes out of the ESA mode and returns
6. If the REX tests pass, the system tests the ESA module that uses the other

Escalation to manual maintenance

Manual maintenance may be required for certain testing conditions. There is
no MAP display to indicate if a Star Hub is in ESA mode because the CC
cannot query the state of the Star Hub when the communication between them
is broken. When the Star Hub is in ESA, the Star Hub is marked as SysB or
CBsy. This is a transient state which will change to SysB.
During the exit time-out period, the STAR MAP display shows the unit that
was requested to leave ESA in the time-out countdown. This status is updated
approximately every 10 s. When the exit process begins, the time-out
software, Star Hub units, and UMP. If one of these preliminary tests fails,
REX tests are not run.
the other unit goes to the takeover mode. The unit in the SysB state has
messaging links switched from the host to the ESA module.
to message to the ESA software under ESA conditions.
the tones test, a comparison of RCP control, and ESA software status
bytes.
to service.
Star Hub unit.
DMS-100 Family NA100 Star Remote System XPM15 and up
ESA maintenance overview 5-21