Allen-Bradley MicroLogix 1200 - Using Modems with Micrologix 1200 Programmable Controllers

Publication 1762-UM001D-EN-P - March 2004
Connecting to Networks via RS-232 Interface E-3
Example DF1 Half-Duplex Connections
Using Modems with MicroLogix 1200 Programmable Controllers
The types of modems you can use with MicroLogix 1200 controllers
include the following:
• dial-up phone modems
A MicroLogix 1200 controller, on the receiving end of the
dial-up connection, can be configured for DF1 Full-Duplex
protocol with or without handshaking. The modem connected
to the MicroLogix controller should support auto-answer. The
MicroLogix 1200 supports ASCII out communications. Therefore,
it can cause a modem to initiate or disconnect a phone call.
• leased-line modems
Leased-line modems are used with dedicated phone lines that
are typically leased from the local phone company. The
dedicated lines may be in a point-to-point topology supporting
Full-Duplex communications between two modems or in a
multi-drop topology supporting Half-Duplex communications
between three or more modems.
TERM
A
B
COM
SHLD
CHS GND
TX
TX PWR
TX
DC SOURCE
CABLE
EXTERNAL
TERM
A
B
COM
SHLD
CHS GND
TX
TX PWR
TX
DC SOURCE
CABLE
EXTERNAL
TERM
A
B
COM
SHLD
CHS GND
TX
TX PWR
TX
DC SOURCE
CABLE
EXTERNAL
Rockwell Software RSLinx 2.0 (or
higher), SLC 5/03, SLC 5/04, and
SLC 5/05, or PLC-5 processors
configured for DF1 Half-Duplex
Master.
RS-232
MicroLogix
1500 (Slave)
SLC 5/04 (Slave)
MicroLogix
1000 (Slave)
SLC 5/03 with
1747-KE Interface
Module (Slave)
MicroLogix
1200 (Slave)
Modem