Data Adapters - AT&T MERLIN LEGEND Installation & Maintenance Manual

Installation

Data Adapters

Adapters are needed to connect data equipment to the control
unit. The kind of adapter used depends on whether or not the
data is analog or digital. For analog data a modem or modem
pool is used; for digital data an ISDN 7500B Data Module is
used.
ISDN 7500B Data Module
The ISDN 7500B Data Module is used to connect a digital data
terminal to the system on a 008 MLX module. The data module is
used at the digital data station to make and receive data calls.
When a data terminal is used to make calls, the keyboard is used
to dial the number. Instead of converting digital data signals to
analog signals as a modem does, the 7500B maintains a digital
data format that allows transmission to another digital station or
over the Integrated Services Digital Network Primary Rate
Interface (ISDN-PRI) telephone network.
The ISDN 7500B Data Module provides an RS-232 interface for
asynchronous data terminal equipment operating at speeds up
to 19.2 kbps. The data module also provides a CCITT V.35
interface for synchronous data terminal equipment operating at
speeds up to 64 kbps. (Optional enhancement boards must be
ordered separately.)
The 7500B can be setup to handle a variety of data
communications equipment (DCE) and is the only digital adapter
that can be used with the system.
The 7500B front panel has the following (see Figure 33):
POWER/TEST LED. Lights when power is supplied to the
7500B; flashes when 7500B tests are performed.
3-56 Data Adapters