NEC Neax 2400 Ipx System Operations And Maintenance Manual

NDA-24307 CHAPTER 5
Page 373
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FAULT REPAIR PROCEDURES
Table 5-4  Timings for Trunks
ITEMS FOR STATUS 
SUPERVISIONCONDITIONS FOR SUPERVISION TIMING SPECIFICATIONS
1 Detection of Call 
TerminationRing Down System
Detection by ringing signal (20Hz) from 
the opposite office.
Loop System
Detection by loop from the opposite office.
E&M System
Detection by incoming signal (ground or 
–48V) on E (RG2) lead.Ringing signal of more than four 
cycles is detected within 800 ms.
Detection within 16 ms after...

CHAPTER 5 NDA-24307
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FAULT REPAIR PROCEDURES
Table 5-5  Timings for Senders
ITEMS FOR STATUS 
SUPERVISIONCONDITIONS FOR SUPERVISION TIMING SPECIFICATIONS
1 Sender Acknowledge Wait 
Ti merTiming limit for waiting to receive connection 
acknowledgement signal from the opposite 
office after seizing the opposite office.4 sec. (standard) 
Timing can be assigned using ASYD 
SYS 1 Index 130 command.
2 Sender Prepause Timer Time from sender seizure till sending of the 
1st digit where connection...

NDA-24307 CHAPTER 5
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FAULT REPAIR PROCEDURES
2.2 Trunk Control
Trunk circuit cards are controlled from the CPU via the MUX. Each trunk line in a specific trunk circuit
card is controlled by the Port Microprocessor (PM) in a trunk circuit card. Figure 5-2 shows the control
route of the trunk circuit card.
Figure 5-2   Controlling Trunk Circuit Cards and Speech Path
Control Signal
MDF
TRKPM
TRK
Control Signal
ORT/SND
LT Cable
LT Cable
TRK
TRKPMControl Signal
COT/TLT
TRK
TRK
ORT/SND
TRKPM...

CHAPTER 5 NDA-24307
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FAULT REPAIR PROCEDURES
2.3 Trunk (ORT, SND, CFT) Fault
Note:If a circuit card is replaced because only one line is faulty, no
other lines in that circuit card can be used until the
replacement is complete.
When only one line is faulty Place the faulty line into make-busy state.
For ORT/SND, set MB switch of
each circuit to ON position.
For CFT, place it into make-busy
state using command MBTK.
Replace  the  circuit  card  with  spare. Set MB switch UP and extract the...

NDA-24307 CHAPTER 5
Page 377
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FAULT REPAIR PROCEDURES
2.4 Trunk (COT, TLT, DTI) Fault
Note 1:If a circuit card is replaced because only one line
is faulty, any other lines in that circuit card cannot
be used until the replacement is complete.
Note 2:If the polarities of the external line is reversed, it
is detected in the form of Trunk Ineffective Hold.
When OPE lamp on the trunk circuit card
does not illuminateConfirm that MB switch of the trunk circuit
card is in ON position (UP side).
Use ATRK...

CHAPTER 5 NDA-24307
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FAULT REPAIR PROCEDURES
Check the faulty line on the MDF. If the C.O./Tie Line is in Loop Start system:
Isolate the faulty line to C.O. side and
to the system side.
Connect the test telephone to the C.O.
side.
Note 3:Check can be made
only on temporarily
opened C.O./Tie Lines.Confirm that Dial Tone (DT) is heard
and the call is connected to the
destination party at the opposite
office.
Note 4:Cross connection
methods are explained
on the following pages.If C.O./Tie...

NDA-24307 CHAPTER 5
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FAULT REPAIR PROCEDURES
Note:
When performing loop-back connection tests on the trunks at the user’s office,
provide cross connection as follows:
(1) For a COT
Set up a loop-back connection between the C.O. Trunk (COT) to be tested and station line.
The trunk route must be assigned for Loop Start.
(2) For a TLT (for DID)
Set up a loop-back connection between the Tie Line Trunk (TLT) to be tested and another TLT.
If the TLT is a Direct Inward Dialing (DID) Trunk,...

CHAPTER 5 NDA-24307
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FAULT REPAIR PROCEDURES
If the TLT is a 2W E & M System, connect the related leads as shown below:
(3) For a DTI
Set up a loop-back connection between the DTI Trunk to be tested and another DTI Trunk as shown
below:
When the loop-back test is performed at the time of PCM LOSS, FRM LOSS, or MERM LOSS alarm
lamp (red) illuminates. If the alarm lamp goes out, the DTI circuit card side is normal.
When only one DTI circuit card is to be checked, make the following...

NDA-24307 CHAPTER 5
Page 381
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FAULT REPAIR PROCEDURES
3. ATTCON/DESKCON FAULT
This section explains the fault repair procedure when a specific Attendant/Desk Console is in any of the
following faulty conditions.
No speech can be made.
No operations can be made.
3.1 Check Point
When repairing an ATTCON/DESKCON fault, consider the following items:
(1) Check the cable connections on the backplane.
(2) When replacing the ATI circuit card for master ATTCON/DESKCON, the system is placed under Night...

CHAPTER 5 NDA-24307
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FAULT REPAIR PROCEDURES
Figure 5-3   ATT Connector Cabling and Connector Leads Accommodation
LT5 LT11
PIM backplane
MDFATTCON/
DESKCONLT11 is used when PA-CS33 is mounted in slot 23.
LT5 is used when PA-CS33 is mounted in slot 12.
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48BN4801 BN4800
BN4820 BN4821
TAS1B
TAS1A
BN4810
BN4830 BN4831BN4811
TAS0B
TAS0A
B2 A2
B3
A3 PA-CS33 Pin Assignment
Installation CableInstallation Cablefor...