Appendix B BRI wiring chart 213
BCM50 Installation and Maintenance Guide
Appendix B
BRI wiring chart
The digital BRI ISDN lines connects to the BCM50b, BCM50ba, and BCM50be main units
through the BRI ports (RJ-45) on the front of the main units. See the figure BRI ports and pin out
(BCM50b shown) on page 213.
The figure BRI ports and pin out (BCM50b shown) on page 213, the table BRI port wiring on page
213, and the table BRI line numbering on page 214 apply to S-Loop and T-Loop connections.
S-Loop are used to connect S-Loop devices such as video phones, terminal adapters, and Grp 3
Fax machines. The T-Loops are used to connect to the CO/PSTN.
Figure 88 BRI ports and pin out (BCM50b shown)
The table BRI port wiring on page 213 and the table BRI line numbering on page 214 list the
wiring details for the RJ-45 ports.
Warning: For a U-loop connection, the BRI port must be connected only to an NT1
provided by the service provider. The NT1 must provide a Telecommunication Network
Voltage (TNV) to Safety Extra Low Voltage (SELV) barrier.
Table 34 BRI port wiring
Pin Signal Signal on system side
1 No connection No connection
2 No connection No connection
3 + Receive (+Rx) +Tx
4 + Transmit (+Tx) +Rx
5 - Transmit (-Tx) -Rx
6 - Receive (-Rx) -Tx
7 No connection No connection
8 No connection No connection
BRI port pin out
BRI ports
