NEC Neax 2400 Ipx System Operations And Maintenance Manual

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(2) Check the mate CPU’s STBY mode. Also check the mate GT’s STBY mode. Refer to
Figure 6-50. 
STEP 2 Flip the MBR key on the DSP of the active CPU.
Figure 6-51   CPU Changeover via MBR Key (LN)
Note:
If the MBR key remains in the UP position, the CPU stays in its make-busy status. Be sure to return the
key to the DOWN position except in the case of a special purpose.
STEP 3 Confirm the changed lamp indications.
To confirm the CPU changeover, check...

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12.1.4 Forced Changeover of CPU
Figure 6-53 shows how to perform the forced changeover of CPU by key oper-
ation on the EMA (PH-PC40) card. Because the key operation will cause the en-
tire system to initialize, do not rely on this method except as a last resort. The
LPM is mounted in the LN as as example.
Figure 6-53   Forced CPU Changeover
ATTENTIONContents
Static Sensitive
Handling
Precautions Required
12
34
567
8
OFF
12
34
567
8
OFF
12
34
OFF...

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12.1.5 How to Control Switching Block
The Switching Block denoted here includes the following system equipment:
In LN In ISW
TSW (PH-SW12) IOGT (PH-GT10)
MUX (PH-PC36) TSW (PU-SW00)
DLKC (PH-PC20) HSW (PU-SW01)
PLO (PH-CK16-A) PLO (PH-CK16-A/17-A)
CLK (PH-CK18)
GT (PH-GT09)
Perform the required system changeover by using the CMODI/CMOD command or by operating the
relevant key on the IOGT/PLO card. Refer to Table 6-9.
Note:The changeover of IOGT...

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Note 1:
These operations cause a momentary interruption in speech paths. It can be ignored as far as ordinary
telephone calls are concerned. Since interruption might cause bit errors, care should be take when
data communications are involved.
Note 2:When changing over the Speech Path System on a node basis, flip the MBR key on that node’s GT (PH-
GT09) card. Refer to Figure 6-38.
PLO and CLK Changeover in the 
ISW/LN by Key Operation
Note 1
On the...

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12.1.6 Manual System Changeover of Speech Path System
To changeover the ACT/STBY of Speech Path System, the CMODI/CMOD command is normally
used. However, if for some reason the command cannot be used, use the key operations listed below.
Note 1:The command CMOD cannot be used to change over the Speech Path mode on a system basis. This
command is only for the changeover on each node basis.
Note 2:This section gives a detail on how to change the Speech...

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STEP 1 Confirm the active Speech Path System.
(1) Check all the lamp indications below, which are in the same switching block.
Figure 6-55   IOGT/TSW/HSW/DLKC/MUX in ACT Mode
(2) Confirm the STBY mode of mate Speech Path System. Check all the lamp indications be-
low, which are in the same switching block.
 
Figure 6-56   IOGT/TSW/HSW/DLKC/MUX in STBY Mode
 TSW: Active
TSW MBTSW MBR TSW ACT
green
 HSW: Active
MB
HSW ACT
green
 IOGT: Active
MBMBR TSW...

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STEP 2 Flip the MBR key on the active IOGT card in ISW.
Figure 6-57   Speech Path System Changeover via Active IOGT MBR Key
Note:
If the MB key is turned ON (UP), the IOGT card is forcibly placed in a make-busy status. Therefore, do
not operate the MB key by mistake. Also, after the MBR key is flipped, be sure to return the key to the
original position (DOWN).
STEP 3 Confirm the changed lamp indications.
(1) To confirm the imposed Speech Path System...

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Figure 6-58   LED Indications Before and After Speech Path System Changeover
STEP 4 Analyze the displayed system messages.
After STEPs 1 through 3 are performed, the system messages [7-E], [7-F], and [1-T] will
automatically display. Confirm that no errors occurred during the Speech Path System
changeover process.
Note:When the Speech Path System changeover is executed in each LN independently, the system messages
to be displayed at this time are...

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12.1.7 Manual System Changeover of PLO
To change over the system of Phase Lock Oscillator (PLO)/Clock (CLK), use the key operations listed
below at a specific LN/ISW.
Note:Though the PLO/CLK 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/CLK must be independently performed at each LN/ISW.
STEP 1 Confirm the active PLO....

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STEP 2 Flip the MB key on the PLO card.
Figure 6-60   PLO Changeover via MB Key 
Note:
If the MB key remains in the UP position, the PLO system also stays in its make-busy status. Be sure to
return the key DOWN except in the case of a special purpose.
STEP 3 Confirm the changed lamp indications.
(1) To affirm the imposed PLO changeover, check the following lamps on both PLO cards. The
LED indications must change as follows when the PLO system has...