AT&T MERLIN LEGEND Release 2.0 Installation Section page 219

Connecting the Control Unit to the Network Interface
Table 4-27. TB1 Pin Assignments
Pin No. Designation
1
2
4
5
Step 7: Plugging the CSU into an Outlet
Depending on the type of line provided by the local telephone company, the
CSU can be supplied with -48 VDC power on the T1 wire pair from the
network.
If the CSU is not powered from the network, a KS22911-L1 power supply is
required.
Connect the power supply to the rear panel at TB1 as follows:
positive lead to terminal 15
-48 VDC lead to terminal 14
4-42
Installing the Channel Service Unit
Signal
Transmit
T1
R1 Transmit
Receive
T
R Receive