Rockwell Automation Logix5000 Controllers Sequential Function Charts Programming Manual - Manual (Page 16)

Chapter 1 Design a sequential function chart
If Then
• The SFC is the only routine in the program
• The SFC calls all the other routines of the program
Configure the SFC as the main routine for the program.
• The program requires other routines to execute
independent of the SFC
• The SFC uses Boolean actions
1. Configure another routine as the main routine for the
program.
2. Use the main routine to call the SFC as a subroutine.
If the SFC uses Boolean actions, then other logic must run independent of the
SFC and monitor status bits of the SFC.
A step represents a major function of your process. It contains the actions that
occur at a particular time, phase, or station.
A transition ends a step. The transition defines the physical conditions that must
occur or change in order to go to the next step.
Step guidelines
Follow these guidelines.
• Start with large steps and refine the steps in several passes.
Define the steps of the
process
16 Rockwell Automation Publication 1756-PM006F-EN-P - October 2014