AT&T Release 2.0 manual Inserting the Signal Monitor Unit

Connecting the Control Unit to the Network Interface

c.Connect the DC Ioopback pair (if provided by the local telephone company) to terminals 11 and 12.

d.If the CSU is to be locally powered, connect the power supply leads to terminals 14 and 15.

Step 4: Inserting the Signal Monitor Unit

After setting the option switches, plug the signal monitor unit into the right side of the 551 T1 CSU.

The signal monitor unit has six LEDs and six bantam jacks (see Figure 4-10).

Table 4-24and Table 4-25show the functions of the LEDs and the test jacks on the front panel.

21-PIN I/O CONNECTOR

OPTIONS

SWITCH (DIP)

LEDs

Signal Monitor Unit

EQ	EQ	SM SM	SM SM
IN	OUT	MON IN	OUT MON

Figure 4-10. Signal Monitor Unit

4-38Installing the Channel Service Unit