Rockwell Automation Logix5000 Logix5000 Controllers Quick Start - Manual (Page 87)

Publication 1756-QS001E-EN-P - October 2009 87
Program a Project Offline Chapter 5
Enter a Sequential Function Chart
A sequential function chart (SFC) lets you define a sequence of states (steps) through which your machine or
process progresses. The steps can execute structured text, call subroutines, or simply serve as signals for
other logic.
Item Description
A Step is major function of your process. It contains the actions that occur at a particular time,
phase, or station.
B Action is one of the functions that a step performs. To program the action, either enter
structured text or call a subroutine.
C Transition is a true or false condition that tells the SFC when to go to the next step. To
specify the condition, either enter a BOOL expression in structured text or call a subroutine.
D Branch executes more than 1 step at the same time (simultaneous) or choose between
different steps (selective).
E Wire connects one element to another anywhere on the chart.
A
D
E
C
B