Rockwell Automation 2755-DM9, -DM9E High Speed Decoder - Manual (Page 24)

Chapter 3
How the Decoder Operates
3–5
Figure 3.5
Communications Interface Examples (Continued)
PLC TO DECODER USING
AN ASCII MODULE
RS-232
PLC TO DECODER USING A
BASIC MODULE
RS-232
Host Computer
RS-232 or RS-422
COMPUTER TO
DECODER
Catalog No. 1771-DB is a BASIC I/O Module
Catalog No. 1771-DA is an ASCII I/O Module
PLC PLC
1771 I/O Rack
2755-DM9
Decoder
1771-DA
2755-DM9
Decoder
1771-DB
1771 I/O Rack
2755-DM9
Decoder
ALLEN-BRADLEY LOCAL-AREA NETWORK - Using the Catalog No.
2760-RB Flexible Interface Module with the 2760-SFC2 protocol cartridge
and the DM9 in the RS-485 mode, you can multi-drop up to 31 devices on
each port of the 2760-RB module.
PROGRAMMABLE CONTROLLERS - You can connect the decoder to a
programmable logic controller in one of three ways:
•
Through the Allen-Bradley Data Highway.
•
Through a Flexible Interface Module (Catalog No. 2760-RB). This
module can be used to create an RS-485 Local Area Network or
point-to-point communications using the RS-232 or RS-422
communications interfaces.
•
Directly, using a Catalog No. 1771-DB BASIC module or 1771-DA
ASCII I/O module.
HOST COMPUTERS- In most cases, you can directly connect your host
computer to the decoder using the RS-232 or RS-422 interface. The decoder
can also communicate with an industrial computer through the Allen-Bradley
Data Highway.