Developing Programs; Configuring Tasks - Allen-Bradley SoftLogix 5800 User Manual

Chapter 2 What is the SoftLogix System?

Developing Programs

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The controller's execution model is a preemptive, multitasking system that is
IEC 1131-3 compliant. This environment provides the following:
• Tasks to configure controller execution
• Programs to group data and logic
• Routines to encapsulate executable code written in a single
programming language
Figure 2 - Control Application
Task 32
Task 1
Program 32
Program 1
Program (local)
Main Routine
Fault Routine
Other Routines
Controller (global) Tags

Configuring Tasks

A task provides scheduling and priority information for a set of one or more
programs. You can configure tasks as either continuous or periodic. The
SoftLogix controller supports as many as 32 tasks, only one of which can
be continuous.
A task can have as many as 32 separate programs, each with its own executable
routines and program-scoped tags. Once a task is activated, all of the programs
assigned to the task execute in the order in which they are grouped. Programs can
appear only once in the Controller Organizer and cannot be shared by
multiple tasks.
Rockwell Automation Publication 1789-UM002K-EN-P - January 2015
Controller Fault Handler
Tags
I/O Data
Configuration
Status
Watchdog
System-shared Data