AT&T Release 2.0 manual Connecting the 551 T1 CSU to the 100D Module

Connecting the Control Unit to the Network Interface

The transmit path in the office repeater has an adjustable artificial line; this allows the transmit level to be adjusted to 0, 7.5, or 15 dB to meet the required -15 or -22.5 dB section loss. The receive path contains a fixed

7.5dB artificial line and an Automatic Line Build-Out (ALBO) circuit, which automatically compensates for signal levels in the range of 0 to -27.7 db.

Step 6: Connecting the 551 T1 CSU to the 100D Module

a. Connect the 100D module to the CSU rear panel (see Figure 4-9).

NOTE:

The maximum length of cable from the 100D module to the CSU for line compensation is 655 ft (200 m).

Table 4-26 shows the pin assignments for the rear panel connections.

Table 4-26. CSU Rear-Panel Pin Assignments

	100D Module			551 T1 CSU
PIN #	DESIG	SIGNAL	D-CONN		DESIG	SIGNAL
1	T1	RCV (tip)	3		T	XMT (tip)
2	R1	RCV (ring)	11		R	XMT (ring)
4	R	XMT (ring)	9		R1	RCV (ring)
5	T	XMT (tip)	1		T1	RCV (tip)

b.Connect the network interface cord to pins 1, 2, 4, and 5 on terminal block 1 (TB1) on the rear panel of the CSU.

Installing the Channel Service Unit 4-41