SYSTEM OPERATIONS

12.1.7 Manual System Changeover of PLO

To change over the system of Phase Lock Oscillator (PLO), use the key operations listed below.

Note: Though the PLO belongs to the Switching Block as explained in Section 12.1.5, its ACT/STBY Switching Network is separate from that of the Speech Path System. Therefore, the changeover of the PLO must be independently performed.

WARNING

Improper key operations may result in a system down. Operate the related keys, using extreme care.

STEP 1 Make sure the PLO system is active.

(1)When the PLO system is active, ACT or OPE lamp on the PLO card lights green. If the LED is OFF, the system is STBY mode.

(2)Check the mate PLO’s STBY mode. Refer to Figure 6-54.

WARNING The changeover of PLO system can be done only when the mate PLO is in STBY mode. Do not attempt the changeover if the mate PLO is closed.

green

ACT/OPE Note

MB

PLO (Front View)

ACT/OPE Note

MB

PLO

PLO: Active

PH-CK16 PH-CK17 PH-CK16-A PH-CK17-A

 

PLO

PH-CK16

 

 

PH-CK17

 

 

PH-CK16-A

PLO: STBY

 

PH-CK17-A

 

 

Legend

 

 

: Lamp is ON

: Lamp is OFF

Note: ACT lamp for PH-CK16/PH-CK17, OPE lamp for PH-CK16-A/PH-CK17-A.

Figure 6-54 PLO in ACT/STBY Mode

CHAPTER 6

NDA-24300

Page 472

Issue 1

Page 499
Image 499
NEC NDA-24300 manual Manual System Changeover of PLO, PLO in ACT/STBY Mode