Nortel Passport 15000, Установка и обслуживание оборудования, Страница: 819 / 874

Chapter 17 Hardware procedures 819
Passport 15000, 20000 Hardware Installation, Maintenance, and Upgrade 5.2S2
Replacing the alarm/BITS module in a Passport 20000
Replace an alarm/BITS module in a Passport 20000 to restore external timing
signals to the CPs or sending the shelf alarm data to the alarm module.
Prerequisites
• You must be familiar with “Safety considerations and best practices”
(page 53).
• The PEC for an alarm/BITS module in a Passport 20000 is one of:
— NTPN12 for balanced DS1 (shielded twisted pair), matched with CP
type NTHW06
— NTPN78, for the external sync cable wire-wrap assembly NTHW75
(matched to the DS1 CP type NTHW06)
— NTPN13 for balanced E1 (shielded twisted pair), matched with CP
type NTHW08
— NTPN13 for balanced E1 (coax) with kit NTPN81 which converts
the signal to unbalanced E1, matched with CP type NTHW08
Procedure steps
1 At the rear of the frame, locate the alarm/BITS module. See the figure
“Location of the alarm/BITS module and cable connections in a
Passport 20000” (page 821)
2 Disconnect the alarm and BITS cables from the alarm/BITS module.
3 Unfasten the large slotted captive screw on the alarm/BITS module.
4 Remove the module by pinching the left captive screw with your left hand
and place your right fingers behind the edge labelled with Jn at the middle
right portion of the module. Pull the module straight away from the switch.
5 Put the module aside.
6 While still wearing a wrist strap, hold the replacement module firmly and
pinch the left captive screw with your left hand and place your right fingers
behind the edge labelled with Jn at the middle right portion of the module.
7 Align the module with the vacant opening and then align the connector on
the module with the connector at the rear of the opening.
8 Gently push the module straight in until its faceplate is flush with the
surrounding surfaces.