Fault Detecting Function - NEC Univerge SV8500 Operation And Maintenance Manual

7.4 Fault Detecting Function

The system finds a fault by its fault detecting circuit and the fault detecting program. Once a fault occurs,
the system initiates a remedial action such as system changeover, make-busy setting, or restart processing
by the automatic diagnosis function. This action reduces the influence of the fault so that system servicing
may be minimized. The result of the process taken and the fault situation are indicated for equipment
concerned.
Among the faults, those related to speech path (noise, one-way speech, speech inability, etc.) are not
detectable. Since these fault reports are obtained from a station or operator, periodic trunk tests must be
performed without failure to detect faults related to speech path.
Figure 1-11 shows an outline of fault detection. Figure 1-12 and Figure 1-13 show a block diagram of fault
detection.
Indication of
Fault Occurrence
System Messages
PCPro
printer, etc.
ALM
Indication of
Alarm Lamp
on EMA card
: Cards in SV8500 Server
Figure 1-11 Fault Detection General Diagram
Information
Collection and Diagnosis
CPU
card
EMA
card
– 29 –
CHAPTER 1
Example of Faults
Fault of line/trunk card
TSW write failure,
Fault of clocks, etc.
Abnormal temperature,
power supply failure,
fuse blowing, etc., within
the equipment frame
General