AT&T MERLIN LEGEND Release 2.0 Equipment And Operations Manual page 114

Hardware Components
Multipurpose Enhancement Board. Provides an RS-366 Automatic
Calling Unit (ACU) interface and converts the RS-232 interface on the
main circuit board from asynchronous to synchronous. A V.35 adapter
cable must be ordered separately to operate at the lower data rates and
also at data rates of up to 56 and 64 kbps. Without the adapter cable,
data rates are limited to 1200, 2400, 4800, 9600, and 19,200 bps.
High-Speed Synchronous Interface Enhancement Board. Provides a
V.35 interface at synchronous data rates of 48, 56, or 64 kbps. A V.35
adapter cable that converts the 25-pin male connector on the board to
the industry-standard 34-pin V.35 interface is included.
Data Module Features
The 7500B Data Module offers the following features:
Asynchronous Features
RS-232 interface
Asynchronous full-duplex operation
Selected data rates of 300, 1200, 2400, 4800, 9600, and 19,200 bps
Data options set via the data terminal attached to the RS-232 interface
Ability to change options without dropping a data call
Autobaud (also called data metering or speed matching)— the ability to
adjust the speed of transmission to match the speed of the data terminal
being called
Auto-adjust—the ability to adjust to the speed and parity of the data
terminal being used
Call setup (dialing) from the keyboard of an ASCII data terminal by using
the local command (CMD) mode or AT mode
Automatic or manual answering of incoming data calls
Synchronous Features with Multipurpose Enhancement Board
RS-232 interface
Half- or full-duplex operation using
1200, 2400, 4800, 9600, and 19,200 using data transport Mode 2
Half- or full-duplex operation at 56 kbps via the V.35 interface adapter
cable
Full-duplex operation at 64 kbps via the V.35 interface adapter cable
Automatic answering of incoming data calls
2-40 Adapters and Adjuncts
RS-232 interface at data rates of
the