Rockwell Automation Logix5000 Logix5000 Controllers Quick Start - Manual (Page 19)

Publication 1756-QS001E-EN-P - October 2009 19
Program and Test a Simple Project Chapter 1
Ladder Logic
For a Logix5000 controller, you enter your logic in routines.
When you create a project, the software automatically creates a main routine that uses the ladder diagram
programming language.
Item Description
A A routine provides the executable code (logic) for a program (similar to a program file in a
PLC or SLC controller).
B There is one main routine you assign for each program.
• When the program executes, its main routine automatically executes.
• Use the main routine to control the execution of the other routines in the program.
• To call (execute) another routine (subroutine) within the program, use a Jump to
Subroutine (JSR) instruction.
C A subroutine is any routine other than the main routine or fault routine. To execute a
subroutine, use a Jump to Subroutine (JSR) instruction in another routine, such as the main
routine.
A
B
C