Plo - Philips Sopho 2000 IPS User Manual

PLO

The PLO (Phase Locked Oscillator) equipped on the MP card is responsible to synchronize the system to
the digital network clock.
When the PBX is a clock receiver office, the PLO generates the clock signals according to the source clock
received from the source office within the network. The source clock signals are extracted at DTI cards
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 arrive from either route 0 or
route 1 due to a transmission 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 route 0 and route 1.
Figure below shows an example of clock supply route when the system is a receiver office.
SOURCE OFFICE
TDSW
SOURCE
CLOCK
~
PLO
NOTE: DTI0 and DTI1 must be mounted in PIM0.
Clock Supply Route
SUB-SOURCE OFFICE
DTI DTI
DTI
RECEIVER OFFICE
DTI
– 272 –
TDSW
DTI
DTI
PLO
TDSW
DTI
DTI
PLO
DIRECT DIGITAL INTERFACE
RECEIVER OFFICE
TDSW
DTI0
DTI1
PLO
PBX NOTE
: DIRECTION OF CLOCK
SIGNAL SUPPLY
NWA-008845-001 Rev.5.0
PLO
32ch1005.fm
JULY/01/2006