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Rockwell Automation Publication 1769-UM022C-EN-P - June 2018
Chapter 8
Elements of a Control Application
Programs
The controller operating system is a preemptive multitasking system that is in
compliance with IEC 1131-3. This system provides the following:
• Programs to group data and logic
• Routines to encapsulate executable code that is written in one
programming language
Each program contains the following:
• Local Tags
• Parameters
• A main executable routine
• Other routines
• An optional fault routine
Figure 27 - Program in a Control Application
Figure 28 - Programs in Application
Task 32
Task 1
Configuration
Status
Watchdog
Program 100
Program 1
Main Routine
Fault Routine
Program
(Local Tags and
Parameters)
Other Routines
Controller (global) Tags
I/O Data
System-shared Data
Controller Fault Handler
Control Application
Controller Organizer
Logical Organizer