Clock Signal Synchronization Test - NEC NEAX 2000 IPS System Manual

Clock Signal Synchronization Test

This test checks to see if the PLO keeps synchronizing with the external clock signals, when the external
clock signals from network have input again after they have stopped once. Do the following steps using
"In Service" transmission lines.
(1) When providing one clock supply route
STEP1: On the DTI0/CCT0 card extracting clock signals, set the switches as follows to stop the external
clock signal input.
• 30DTI0/30CCT0 card: SW-1 and SW-2 to OFF
• 24DTI0/24CCT0 card: SW0-1 and SW0-2 to OFF
– The CLK lamp on the MP card goes out.
STEP2: Originate an outgoing call via trunk.
STEP3: After an outgoing connection via trunk has been established, confirm interoffice synchroniza-
tion and speech quality as follows:
• On the DTMF telephone set, keep pressing any dial button.
• Check to see if noise periodically occurs on the DTMF signals coming from the calling sta-
tion in the opposite office.
• Do the above test again in the opposite direction.
STEP4: On the DTI0/CCT0 card, restore the switches as the state before testing to input the external
clock signals.
• 30DTI0/30CCT0 card: SW-1 to ON, SW-2 to OFF
• 24DTI0/24CCT0 card: SW0-1 to ON, SW0-2 to OFF
– The CLK lamp on the MP card lights.
STEP5: Originate an outgoing call via trunks.
STEP6: After an outgoing connection via trunks has been established, confirm interoffice synchroniza-
tion and speech quality with the procedure shown in STEP 3.
NOTE: If noise periodically occurs, replace the MP card after checking the switch settings on the MP
card, and do the above test again.
CHAPTER 5 OPERATION TEST
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PLO OPERATION TEST
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