Chapter 1
Controller messages
This section describes how to transfer (send or receive) data between controllers
by executing a message (MSG) instruction. It explains cache connections and
buffers so you can correctly program the controller.
The following data types are supported when sending CIP messages.
• SINT
• INT
• DINT
• LINT
• REAL
In addition, you can send a message with any structure type that is predefined,
module-defined, or user-defined.
See “Convert between INTs and DINTs (on page 16
)” for more information on
INTs and DINTs.
For complete details on programming a message instruction, see the Logix5000
Controllers General Instruction Reference Manual, publication 1756-RM003.
Example: Execute a Message (MSG) Instruction
If count_send = 1
and count_msg.EN = 0 (MSG instruction is not enabled)
then execute a MSG instruction that sends data to another controller.
Rockwell Automation Publication 1756-PM012F-EN-P - October 2014 9
