NEC Univerge SV8500 Operation And Maintenance Manual page 78

- Symbols -
: Circuit Card in PIR/TSWR
: Card in SV8500 Server
: Faults to be detected
: Speech Path
: Fault Information flow
PCPro
printer, etc.
(Note) Fault Information:
MJ, MN faults
Power OFF, blown fuse
CPU faults
Speech Path faults
RGU, Howler faults
CPU Clock faults
SYMBOL
CPU Central Processing Unit
EMA Emergency Alarm Controller
IOC I/O Controller
LC/TRK Line/Trunk
GT/EXB Gate card
(a) Main Faults
Faults that may occur in the system can be generally categorized into Processor System Fault, Speech
Path System Fault, Line/Trunk Fault, etc.
• Processor System Fault
The CPU alarm detecting circuit continuously monitors whether the CPU is working normally. If a
fault is detected, the CPU calls up the diagnostic program, that identifies the cause of the fault and
determines whether the fault is temporary or permanent. When the fault affects system operations,
Active/Standby status of the CPU is changed over (provided that the system has dual configuration).
• Bus System Fault
Figure 1-13 Fault Detection Block Diagram (4-IMG)
CPU
(IOC)
Software abnormal
Information
behavior monitor
(Note)
MEANING
EXB
Ready
Clock
Fault
EMA
SYMBOL
PWR Power Supply
DLKC Data Link Controller
TSW Time Division Switch
MUX Multiplexer
TSWM Time Division Switch Module
– 31 –
CHAPTER 1
Firmware
faults
MUX
LC/TRK
PWR
TSWR
PWR
TSW
Ready
Clock
GT
PLO
Ready
Clock
Power off,
blown fuse
MEANING
General