CHAPTER 5
ND-45383 (E)
Page 120
Revision CD 1.0
2.2 How to Proceed with Diagnostic Work from System Message
The diagnostic procedure you should follow, after seeing a system message, is illustrated in Figure 5-2.
Judge whether the fault status coincides with the indicated status, following the sequence beginning with
START.
STEP 1:
Judge whether the fault coincides with the fault status (1).
STEP 2:
If the fault status does coincide, the fault is indicated by (2). Repair the fault according to Section
4: “FAULT REPAIR PROCEDURE”. Otherwise, proceed to (4).
STEP 3:
Perform the work indicated by (4).
The result of the work (4) is broken down as indicated by (5).
STEP 4:
Make a judgment as to whether the result of work (4) coincides with the status indicated by (6).
If so, the fault is indicated either by (7) or by (2). If not, proceed to the next step.
STEP 5:
Perform the work indicated by (8), and if the result of the work is the same as the status indicated,
the fault is indicated by (2). If the fault repair work indicated by (2) affects another normal line, recheck the
work as indicated by (9).
The meaning of the symbols used in diagnostic work are explained below.
If, as a result of a fault diagnosis, the faulty condition cannot be reproduced and is judged to be temporary,
this information is displayed.
In this case, clear the indicated alarm and the system message using the RALM command and place the
system under supervision to see if the same fault recurs.
While a fault repair is in progress, perform various operations such as system changeover, initializations,
etc. When such operations are performed, they affect the normally operating station lines, attendant con-
soles, trunks, etc. in the form of momentary disconnection, speech interruption, forced release of calls in
progress, etc.
By comparing the urgency of the required fault repair with the above-mentioned effects on the lines, trunks
etc., determine the proper timing for performing the necessary recovery work.
(1)
FAULT SUPERVISION
(2)
CHECK OF WORK
