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Use a modem with your interface module, Choose the module’s functionality – Rockwell Automation 1747-KE DH-485/RS-232C INTERFACE MODULE User Manual

Page 8

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8 DH485/RS-232C Interface Module

Publication 1747-IN006B-EN-P - October 2005

Use a Modem with Your Interface Module

The interface module can be connected to the following direct connect modems.

• Manual
• Data Terminal Equipment (DTE) Controlled Answer
• Auto Answer
• Direct Connect

The manual modem is usually an acoustically-coupled modem. A person on each
end of the phone line establishes the connection. The handset is inserted into an
acoustic coupler to complete the connection.

A DTE Controlled Answer modem is attached directly to the phone lines. The
interface module acts as the DTE, which controls the modem via the DTR, DSR, and
DCD signals. The module incorporates time-outs and tests to properly operate these
types of modems.

An Auto Answer modem has self-contained time outs and tests. They can answer
and hang up the phone automatically. The module has no means of controlling an
auto-dial modem, but it can be used in conjunction with a separate auto–dialer.

A Direct Connect modem connects to a dedicated, leased phone line and remains
active at all times.

Choose the Module’s Functionality

Your series B interface module has the ability to function as a series A interface
module. This feature is useful if you are replacing a series A module with a series B
module.

The module’s functionality depends on the placement of the JW4 jumper.
Horizontal placement of the jumper gives the module functionality equivalent to a
series A interface module, while vertical placement of the jumper accesses the
added functionality of a series B interface module.

Refer to page 7 for location of jumper JW4.

Figure 4 Module Functionality

Series A Functionality
(mod. config. ID=4209)

Series B Functionality
(mod. config. ID=3509)

Horizontal Configuration

Mode

Horizontal Run

Mode

Vertical Run

Mode

Vertical Configuration

Mode