Meridian communications unit, Functional description – Nortel Networks M3110 User Manual
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Appendix C: Meridian Modular Telephones add-on modules installation
553-3001-367 Standard 3.00 August 2005
Meridian Communications Unit
The Meridian Communications Unit (MCU) provides a stand-alone version
of the Meridian Communications Adapter (MCA).
Functional description
The Meridian Communications Unit (MCU) enables data to be transmitted
and received using PSDS, over either the public network or a private network.
The MCU, which replaced the QMT21C, is designed for domestic and
international use, with transmission speeds up to 19.2 kbps asynch and
64 kbps synch, integrated display, and self diagnostics.
The MCU supports autodialing, ring again, and speed calling, as well as
autobauding and automatic parity detection. The MCU can be used for the
following:
•
Video conferencing
Table 71
RS-232-C signals and associated pin numbers for M2317 telephones
Circuit designation
Pin
number
Signal source
EIA
Common
CCITT
DTE
DCE
Name
AA
101
1
X
Frame ground
BA
TXD
103
2
X
Transmit data
BB
RXD
104
3
X
Receive data
CA
RTS
105
4
X
Request to send
CB
CTS
106
5
X
Clear to send
CC
DSR
107
6
X
Data set ready
AB
GND
102
7
X
Signal ground
CD
DTR
108.2
20
X
Data terminal ready
CE
RI
125
22
X
Ring indicator