Trunk (Cot, Tlt, Dti) Fault - NEC Univerge SV8500 Operation And Maintenance Manual

3.2.4

Trunk (COT, TLT, DTI) Fault

If a circuit card is replaced because only one line is faulty, any other lines in that circuit card cannot be
Note:
used until the replacement is complete.
If the polarities of the external line are reversed, it is detected in the form of Trunk Ineffective Hold.
Note:
(1) When OPE lamp on the trunk circuit card does not illuminate.
(a) Confirm that MB switch of the trunk circuit card is in ON position (UP side).
(b) Confirm that trunk data (ATRK command) in the trunk circuit card is assigned.
(c) Replace trunk circuit card with a spare.
(2) When BL lamp is flashing or illuminating on the trunk circuit card.
(a) Confirm that MB switch of trunk circuit card is in ON position (UP side).
(b) Use the MBTK command to confirm that trunk circuit card has not been placed into make-busy state.
(c) Check trunk data (ATRK command) assignment.
(d) Replace trunk circuit card with a spare.
(3) Check the faulty line on the MDF.
[If the C.O./Tie Line is in Loop Start system]
(a) Isolate the faulty line to C.O. side and to the system side.
(b) Connect the test telephone to the C.O. side.
(c) Confirm that Dial Tone (DT) is heard and the call is connected to the destination party at the opposite
office.
Check can be made only on temporarily opened C.O./TIE lines.
Note:
[If C.O./TIE line is any other type than Loop Start]
(a) By cross connections on the MDF, connect the faulty line to a normal trunk.
(b) By a designated connection from the ATTCON/DESKCON, seize the
trunk connected with the faulty line.
(c) After the trunk has been seized, check to see if a call can be originated.
When the connection is not set up, the C.O./TIE line is faulty.
Note:
[When the connection is set up]
• Replace the Dterm with a spare.
Cross connection methods are explained on the following pages.
Note:
CHAPTER 5 Operation Procedure for System with PIR
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