Nortel QMT12 ADM, Руководство пользователя

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Equipment description Page 23 of 80
Meridian Data Services Description
The ADM replaces base-band modems, acoustical couplers, and limited
distance data sets for in-house data transmission activities. It extends several
SL-1 station calling features to data calling use when installed on a standard
SL-1 telephone. The ADM also provides switched, dial-up access from
multiple in-house terminal equipment to shared dedicated or voice-grade
modems for external data calling.
QMT7 ADM
The QMT7 provides asynchronous, half or full-duplex operation over 2- or
4-wire transmission lines and, depending on the terminal or modem used,
transmission speeds of 50, 75, 110, 134.5, 150, 300, 600, 1200, 1800, 2000,
2400, 3600, 4800, 7200 and 9600 bps. It accommodates a serial character data
format of 5, 6, 7 or 8 data bits and 1, 1.5 or 2 stop bits (or as defined by the
data unit).
The ADM is compatible with Bell 103/212/202 compliant modems and
provides an EIA RS-232-C interface to data terminal equipment or modems.
It converts the signals from the data equipment to full-duplex digital
(128 kbits/sec, BPRZ encoded) to send to the Data Line Card (DLC) in the
Meridian 1.
The ADM provides for re-down-line loading of RS-232 control signals. It
also provides the following Data Call features:
• Flexible numbering plan for data stations
• Auto-answer capability
• Originate capability
• Voice path integrity in ADM power loss situations
• Alternate or simultaneous voice and data calling per data station
• Distinctive buzz for incoming data calls
• Distinctive connect tone
• Power Fail Protection
Note: Not all of the data modules have these features, i.e., not all have
distinctive buzz, alternate or simultaneous voice and data capability. See
module specifications.