Nortel Networks BCM200 Connecting the BCM expansion unit to the BCM main unit, DS256 cable pinout

Chapter 7 Installing an expansion unit 103

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 Table 24 and Figure 60.

•the cable must be shielded

•the cable must be exactly 5 m long

Table 24 DS256 cable pinout

	Expansion unit	Main unit
Signal name	PIN	PIN	Circuit name		Color
TXD +	1	1	PAIR 3 (-)		White-Green
TXD -	2	2	PAIR 3 (+)		Green
SYNC +	3	3	PAIR 2 (-)		White-Orange
CLK +	4	4	PAIR 1 (+)		Blue
CLK -	5	5	PAIR 1	(-)	White-Blue
SYNC -	6	6	PAIR 2	(+)	Orange
RXD +	7	7	PAIR 4	(-)	White-Brown
RXD -	8	8	PAIR 4	(+)	Brown

Figure 60 DS256 cable

Pin 1

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.

BCM200/400 4.0 Installation and Maintenance Guide