Csu Front-Panel Test Jacks - AT&T MERLIN LEGEND Installation & Maintenance Manual

Installation
Table 3-19 CSU Front-Panel Test Jacks
Jack
DIAGNOSTIC
EQ IN
EQ OUT
SM IN
SM OUT
EQ MON
SM MON
+1, -1
551 T1 L1 CSU
The 551 T1 L1 CSU (see Figure 24) performs many of the same
functions as the ESF T1 CSU, but it does not support B8ZS and
therefore does not support the 64-kbps clear channel. Also, it
does not support extended superframe (ESF) format; if a network
requires this format, the ESF T1 CSU must be used.
Mount the 551 T1 L1 CSU in a relay rack, in various types of
cabinets, or as a stand-alone unit. This CSU consists of the
following components:
chassis with top and rear cover
Signal Monitor Unit (plug-in)
Office Repeater (plug-in)
Provides
Access via 310 jack to the 4-kbps data link
Break-in access to transmit line to system
Break-in access to receive line from system
Break-in access in transmit path to network
Break-in access in receive path from network
Monitor access to received signal from system
Monitor access to received signal from network
Test points for measuring simplex current from
network to critical circuits (if provided)
Channel Service Unit 3-37