Rj-21 telephony connector – Nortel Networks BCM50 User Manual
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Chapter 2 Introducing the BCM50 hardware
NN40020-302
RJ-21 telephony connector
Use the RJ-21 telephony connector to connect a 25-pair (RJ-21) cable to the main unit. Then use
these 25 pairs of wires to connect to the following telephony devices (see
•
Four analog lines (standard main units only)
Use these connections for analog trunks from the Public Switched Telephone Network
(PSTN). The four analog lines on the RJ-21 telephony connector are not available on the BRI
series (b-series) main units.
•
Four analog telephones
Use these connections for analog telephony devices such as single-line telephones, fax
machines, and modems.
•
Auxiliary ringer
Use this connection for an auxiliary ringer (customer supplied). The BCM50 system uses the
auxiliary ringer to control the cadence of an auxiliary ringer. You must use this output in a
low-current, low-voltage application only. Do not use this output for switching the auxiliary
ringer directly.
•
Page output
Use this connection to connect an internally generated voice-paging signal to an external
paging amplifier (customer supplied).
•
Page relay
When you use the page output to connect an external paging amplifier, you also use the page
relay. The page relay connects to a floating relay contact pair. The BCM50 system uses the
page relay to control the external paging amplifier.
•
Music input
Use the Music input to connect an external music source that supplies a signal to held lines
(music on hold) or telephone speakers (background music). The input source can be any
available radio or music source approved for connection to the network. If you use this
connection, do not use the Music input jack on the main unit faceplate.
•
Twelve digital telephones
Use these connections for digital telephones. For a list of digital telephones that are compatible
with the BCM50 system, see
Warning: External equipment connected to the auxiliary ringer, page relay, page output,
and music-on-hold interfaces must use safety extra low voltage (SELV).
All four interfaces are SELV and the external equipment connected to these interfaces
must be SELV. If these interfaces are not SELV, you must use external line isolation units
(LIU).
Note: The analog trunk interfaces and analog telephony device interfaces on the RJ-21
telephony connector are compatible with the North American telephony interface
standards only.
If your BCM50 system is in a country that uses a different telephony standard, you must
use media bay modules for your analog trunks and media bay modules or ATAs for your
analog telephony devices.