3
Telephone Connections
This system is configured for a “TIE LINE” connection to a
Nortel/Avaya
telephone system.
The telephone system is supplied and installed by those other than E.F. Bavis and Associates.
There will be an E&M Tie Line Card in the telephone system, which is located in the electrical
equipment room. The connections to the telephone use standard CAT 5 wiring. The termination
is a type 568B. The connectors are RJ45. The E&M connections to the
Nortel/Avaya
system are
referenced to the system ground and system battery. These reference levels are included in the
RJ45 connection
In the programming for the “TIE LINES” the following settings are required by the BavSonic
system. Line type = E&M, Answer = Manual, Answer DISA = NO, Signal = IMMEDIATE,
Gain = NORMAL, Dial Mode = TONE.
Telephone Diagnostics
The WHITE /GREEN STRIPE (E1) wire is referenced to the GREEN (E2) wire. The normal
voltage is 56Vdc with the BROWN wire being positive. After the call button is depressed the
voltage will be less than 1Vdc. This indicates that the intercom is connected to the interface.
This is the “E Lead” sensing. There is a LED for each lane to indicate that the intercom is
connected to the interface.
The BROWN (M1) wire is referenced to the WHITE/BROWN STRIPE (M2) wire. The normal
voltage is 5Vdc with the BROWN wire being negative. The voltage is less than 1Vdc when the
telephone is connected to the interface. This is the “M Lead” sensing. There is a LED for each
lane to indicate that the telephone is connected to the interface.
The BLUE, WHITE/BLUE STRIPE (TRANSMIT) wires are the audio signal coming from the
telephone transmitter going to the intercom speaker. With the lane selected and someone talking
the audio signal is approximately .848Vp-p as measured on an oscilloscope or .3Vrms as
measured on a true rms digital multimeter.
The ORANGE, WHITE/ORANGE STRIPE (RECEIVE) wires are the audio signal coming from
the intercom microphone to the telephone receiver. With the lane selected and someone talking
the audio signal is approximately .848Vp-p as measured on an oscilloscope or .3Vrms as
measured on a true rms digital multimeter.
When connecting to a Cisco phone system, the E&M Telephone Interface system requires one
(1) Transfer or A/B Cat5 patch cable. This cable can be at either at the Interface box or at the
phone server. If there not a Transfer cable, or if there are two cables, the symptom would be that
as soon as the Cat5 cable is connected to the Interface box and the phone server, the phone server
will react as though the call button has been pressed, and/or the line is “Busy”.
