User manual

154 Rockwell Automation Publication 1756-UM001O-EN-P - October 2014
Chapter 10 Develop Applications
Routines
A routine is a set of logic instructions in one programming language, such as
Ladder Diagram (ladder logic). Routines provide the executable code for the
project in a controller. A routine is similar to a program file or subroutine in a
PLC or SLC processor.
Each program has a main routine. The main is the first routine to execute when
the controller triggers the associated task and calls the associated program. Use
logic, such as the Jump to Subroutine (JSR) instruction, to call other routines.
You can also specify an optional program fault routine. The controller executes
this routine if it encounters an instruction-execution fault within any of the
routines in the associated program.
Figure 35 - Routines in a Control Application
Figure 36 - Routines
Controller Fault Handler
Task 32
Task 1
Configuration
Status
Watchdog
Program 1000
Program 1
Main Routine
Fault Routine
Other Routines
Controller (global) Tags
I/O Data System-shared Data
Program (Local
Tags and
Parameters)
Routine
Routine
Routine
Routine
Controller Designer
Logical Designer