Verilink C100 (880-502893-001) Product Manual - Manual (Page 54)

LED Indicators and Diagnostics
4-14 Verilink C100 and C150 T1/FT1 CSU/DSU 6/15/99
Customer Interface
DSX1 monitor jack The CI DSX1 Monitor Jack located on left side of unit permits an
external T-1 tester to monitor either or both the TX and RX pairs
connecting the DSX1 port to the Customer Interface equipment (see
the Figure). When using these jacks the TX and RX pairs are isolated
by a 500 ohm resistors to protect the T-1 signals. These jacks are for
monitor only.
Figure 4-20 C150 T-1 CSU/DSU wiring diagram of DSX1 Monitor Jack
CI T-1 CSU/DSU
TX RX
Customer
Interface
Equipment To
From
500 Ohms