User's Manual

CHAPTER 2 NDA-24300
Page 16
Issue 1
SYSTEM MAINTENANCE OUTLINE
Figure 2-14 Fault Detection Block Diagram
TSW/INT
LC/TRK
MUX
CPU
EMA
PWR
DLKC
GT
To MAT,
Printer, etc.
Alarm Lamps on TOPU
Thermal Reed Relay
TSWM
RDY
Clock
etc.
Howler
Ringing
Circuit
Fault
Note
PWR Supply
Failure,
Fuse Blown
Ready
IOC
Symbols
: Circuit Card
: Main faults to be detected
: Speech path
: Flow of fault information
SYMBOL NAME SYMBOL NAME
CPU
EMA
IOC
LC/TRK
GT
PWR
DLKC
INT
TSW
MUX
TSWM
Central Processing Unit
Emergency Alarm Controller
I/O Controller
Line/Trunk
Gate
Power Supply
Data Link Controller
Speech Path Control Interface
Time Division Switch
Multiplexer
Time Division Switch Module
Information
monitor
C-level
Firmware
Fault
Note:
MJ, MN fault
Power, Fuse blown fault
Temperature, CPU fault
Speech Path System fault (SPE)
RGU, Howler fault
PFT fault
CPU Clock fault
RDY
Clock
Write
etc.