Sfc Operation; Elements Of Sfc - Omron SFC - INTRODUCTION GUIDE Introduction Manual

1-3 SFC Operation

1-3 SFC Operation
This section explains the elements of SFC and the operation of SFC programs.

1-3-1 Elements of SFC

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: Step
A step is an element of SFC programs, and
represents a single process within the overall
process flow. When a step becomes active,
action blocks assigned to that step are
executed.
The first step of a program is referred to as the
"initial step".
: Action Block
An action block contains the step processes
(actions) for a single step.
: Action Qualifier
An action qualifier defines the execution
timing and status retention preference for
each action.
: Action Name
For each action, specify a Boolean variable
(contact) or an action program name.
: Transition
A transition represents the condition that
transfers the active status from the step
before the transition to the step after the
transition.
: Simultaneous Sequence Divergence/
Convergence
A simultaneous sequence divergence is a
structure in which a single transition is
followed by multiple steps. When the transition
condition is satisfied, all of the connected
steps become active simultaneously.
A simultaneous sequence convergence is a
structure in which multiple steps are followed
by a single transition. Active status is
transferred when the transition condition is
satisfied and after all the steps have been
activated.