Nortel Passport 15000, Hardware Installation And Maintenance, Page: 635 / 874

Chapter 17 Hardware procedures 635
Passport 15000, 20000 Hardware Installation, Maintenance, and Upgrade 5.2S2
Making a BITS cable
Make a BITS cable to connect from the timing source directly to the
alarm/BITS module or to one of the prefabricated timing cables to enable
external timing.
Prerequisites
• You must be familiar with “Safety considerations and best practices”
(page 53).
• For cable specifications refer to the section on alarm/BITS module in
241-1501-200 Passport 15000, 20000 Hardware Description.
Procedure steps
1 Each timing connection requires 2 wires. When connecting both the A and
the B timing references, select color-coded twisted pair wires to
distinguish between the 2 (this does not apply to E1 unbalanced
connections).
2 Ensure the size of wire (for example, 22 AWG or 6 mm
2
) can be soldered
to the DB9 connector pins. The wire size depends on the length between
the end points.
3 Locate the CPE timing source at your site.
4 Lay the wires from the timing source up to the connectors J3 and J4 on
the alarm/BITS module at the rear of the Passport 15000 or 20000. Route
the wires up or down the right side of the frame against the cable
management brackets.
5 Connect the wires at the source, using whatever method of connection is
required.
6 Label each timing wire pair at both end points to distinguish which is
reference A and which is reference B.
7 Fasten the wires snugly with tie-wraps to whatever CPE wire support
system leads to the cable management brackets on the switch mounting
apparatus. Leave enough length at the Passport 15000 or 20000 end of
the wire to attach the D-sub connectors.
8 From the DB9 connector kit, insert the rubber grommet over the wires,
wider end first. Repeat on the second pair of timing wires if the redundant
reference is being used. Slide the grommet away from the ends.
9 In preparation for soldering, cut two lengths of wire, approximately 2 cm
(3/4 in.) each. Use the same type and size wire as the timing wire pairs.