Plo - NEC UNIVERGE SV9300 Networking Manual

PLO

The Phase Locked Oscillator (PLO) equipped on the CPU blade is responsible to synchronize the system
with the clock signals from the another office.
When the PBX is a clock receiver office, the PLO generates the clock signals according to the source
clocks received from the source office within the network.
The source clock signals are extracted at CCT blades and supplied to the PLO.
Two clock routes are available: one is the route 0 from the source office, and the other is a standby route
1 from a sub-source office. When no clock signals come from either the route 0 or route 1, due to a trans-
mission line failure, the PLO keeps generating the clock signals at the frequency of the last source clock.
The PLO can receive different frequency of source clocks from the route 0 and route 1.
This figure shows an example of clock supply route configuration.
SOURCE OFFICE
TDSW
SOURCE
CLOCK
~
PLO
Clock Supply Route
SUB-SOURCE OFFICE
CCT CCT
CCT
RECEIVER OFFICE
CCT
TDSW
CCT
CCT
PLO
TDSW
CCT
CCT
PLO
1-3
Chapter 1 CCIS FEATURES
SYSTEM OUTLINE
RECEIVER OFFICE
TDSW
CCT
CCT
PLO
PBX
: DIRECTION OF CLOCK
SIGNAL SUPPLY
NWA-088654-001 Rev.1.0
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