Esa Rom Diagnostics - Nortel DMS-100 Series Maintenance Manual

3-30 ESA maintenance overview
time. Tests of the two units at one time can result in a loss of service for
connected calls. While the REX test tests one unit, the other unit continues
call processing in the takeover mode.
The system tries to prevent accidental attempts to perform maintenance on
an LCM unit that is in ESA mode. To prevent maintenance on an LCM, 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 an LCM unit affects calls that the system starts to
connect. These processes do not affect connected calls. The LCM unit
returns to service before a REX test tests the other unit.
The following actions occur during a REX test:
1 An REX test tests the messaging ability of the peripherals, ESA module,
2 If the preliminary tests pass, one LCM unit goes to the ESA mode and
3 The ESA processor tests the ability of the LCM units to message to the
4 The system performs other diagnostics on the ESA module. Other
5 After the tests are complete, the unit goes out of the ESA mode and
6 If the REX tests pass, the system tests the ESA module that use the other

ESA ROM diagnostics

The ESA processor is provided with a ROM diagnostic test. Operating
company personnel can use the LOADPM command to implement this test.
This test consists of the standard XPM ROM tests, which test the processor
and memory complex, and basic messaging functions. The messaging
functions are the DMS CC to ESA processor messaging capabilities.
297–8351–550 Standard 04.01 August 1999
LCM units, and RMM. If one of these preliminary tests fails, REX tests
are not run.
the other unit goes to the takeover mode. The unit in the ESA mode has
messaging links switched from the host to the ESA module.
ESA module under ESA conditions.
diagnostics are the tones test, and a comparison of LCC control and
6X75 status bytes.
returns to service.
LCM unit.