Plo - NEC NEAX 2000 IVS 2 System Manual

CHAPTER 1 GENERAL INFORMATION
System Outline

PLO

The Phase Locked Oscillator (PLO) is responsible for providing synchronization between the
TDSW and another office. In this system, the internal PLO equipped with the MP card is used.
The PLO generates a synchronized clock signal according to the source clock signals supplied
from the source office within the network, and supplies the generated clock signal to the TDSW.
The PLO is supplied with clock signals extracted from the DTI. The PLO can be equipped with
two clock supply routes; one is the route from the source office, and the other is a standby route
from a sub-source office. When no clock signals from the source and the sub-source office arrive
due to a transmission line failure, the PLO keeps generating the clock signals in phase with the
previous source clock.
Figure 1-2 shows an example of clock supply route configuration.
SOURCE OFFICE
TDSW
SOURCE
CLOCK
~
PLO
Page 6
Figure 1-2 Clock Supply Route
SUB-SOURCE OFFICE
DTI DTI
DTI
RECEIVER OFFICE
DTI
RECEIVER/LOCAL-RECEIVER OFFICE
TDSW
DTI
DTI
PLO
TDSW
DTI
DTI
PLO
TDSW
DTI
DTI
PLO
PBX
:
DIRECTION OF CLOCK
SIGNAL SUPPLY
2
NEAX2000 IVS CCIS System Manual
ND-70918 (E), Issue 1.0