Connecting The Bcm Expansion Unit To The Bcm Main Unit - Nortel BCM200 Installation And Maintenance Manual

Connecting the BCM expansion unit to the BCM main unit

After the expansion unit is installed in the desired location, use the supplied DS256 cable
(NTAB3086) to connect it to the BCM main unit. The cable has the following characteristics:
• all 8 pins must be connected as shown in
• the cable must be shielded
• the cable must be exactly 5 m long
Table 24 DS256 cable pinout
Signal name
TXD +
TXD -
SYNC +
CLK +
CLK -
SYNC -
RXD +
RXD -
Figure 61 DS256 cable
Pin 1
Warning: The timing in the BCM system is critical. Use the correct length cable as
supplied with the expansion unit. The system will not work properly if you connect the
BCM expansion unit using a cable that varies in length.
Expansion unit Main unit
PIN PIN
1 1
2 2
3 3
4 4
5 5
6 6
7 7
8 8
Chapter 7 Installing an expansion unit
Table 24 and Figure 61.
Circuit name
PAIR 3 (-)
PAIR 3 (+)
PAIR 2 (-)
PAIR 1 (+)
PAIR 1 (-)
PAIR 2 (+)
PAIR 4 (-)
PAIR 4 (+)
BCM200/400 4.0 Installation and Maintenance Guide
103
Color
White-Green
Green
White-Orange
Blue
White-Blue
Orange
White-Brown
Brown
Pin 1