Rockwell Automation Publication 1756-PM006I-EN-P - February 2018 5
Table of contents
Studio 5000 environment.................................................................................................... 9
Additional resources .......................................................................................................... 10
Legal notices ........................................................................................................................ 10
Chapter 1
Introduction ........................................................................................................................ 13
What is a sequential function chart? .............................................................................. 14
Define the tasks .................................................................................................................. 18
Choose how to execute the SFC ..................................................................................... 19
Define the steps of the process ......................................................................................... 19
Step guidelines............................................................................................................. 19
SFC_STEP structure ................................................................................................. 20
Organize the steps .............................................................................................................. 23
Sequence ....................................................................................................................... 25
Selection branch ......................................................................................................... 25
Simultaneous branch ................................................................................................. 26
Wire to a previous step .............................................................................................. 27
Add actions for each step .................................................................................................. 28
How do you want to use the action? ...................................................................... 28
Use a non-Boolean action ......................................................................................... 28
Use a Boolean action .................................................................................................. 29
SFC_ACTION structure ......................................................................................... 30
Describe each action in pseudocode ............................................................................... 31
Choose a qualifier for an action ....................................................................................... 32
Define the transition conditions ..................................................................................... 33
Transition tag .............................................................................................................. 34
How do you want to program the transition? ...................................................... 34
Use a BOOL expression ............................................................................................ 35
Call a subroutine in a transition .............................................................................. 35
Transition after a specified time ...................................................................................... 36
Turn off a device at the end of a step .............................................................................. 38
Choose a last scan option .......................................................................................... 39
Use the Don’t Scan option ....................................................................................... 40
Use the programmatic reset option ........................................................................ 41
Use the automatic reset option ................................................................................ 43
Keep something on from step-to-step ............................................................................ 45
How do you want to control the device? ............................................................... 45
Use a simultaneous branch ....................................................................................... 45
Store and reset an action ........................................................................................... 46
Use one large step ....................................................................................................... 47
End the SFC ........................................................................................................................ 48
Use a stop element ...................................................................................................... 48
Restart (reset) the SFC .............................................................................................. 49
Design a sequential function
chart