122 Rockwell Automation Publication 1756-UM001M-EN-P - February 2012
Chapter 6 Serial Communication (1756-L6x controllers only)
Modbus Support
To use ControlLogix controllers with the Modbus protocol, establish a serial port
connection and execute a specific ladder-logic routine.
Two controller projects specific to the Modbus network are available as sample
programs with RSLogix 5000 software. These sample programs include the
following:
• ModbusMaster.ACD
• ModbusSlave.ACD
For information about using these sample programs, see the Using Logix5000
Controllers as Masters or Slaves on Modbus Application Solution, publication
CIG-AP129
.
Additional Resources
Consult these resources for additional information related to serial
communication and the ControlLogix system.
You can view or download publications at http://www.rockwellautomation.com/
literature/. To order paper copies of technical documentation, contact your local
Allen-Bradley distributor or Rockwell Automation sales representative.
Resource Description
ProSoft Technology website, available at http://www.prosoft-technology.com Provides information about multi-vendor modules that can be used to establish a serial
communication network with a ControlLogix system.
Logix5000 Controllers General Instruction Reference Manual, publication 1756-RM003
Explains ASCII instructions and programming.
Using Logix5000 Controllers as Masters or Slaves on Modbus Application Solution,
publication CIG-AP129
Explains how to apply the Modbus sample code in Logix5000 controller projects.