Description Of Sfc Program - Mitsubishi Electric MELSEC-Q Series Programming Manual

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Description of SFC Program

The SFC program consists of steps that represent units of operations in a series of machine operations.
In each step, the actual detailed control is programmed by using a ladder circuit.
Grouping steps into one block in process units allows to create an SFC program that is capable of tracking all the processes
as well as structuring the operation flow in each process.
An SFC program starts at an initial step, executes a step following a transition condition in due order every time that transition
condition is satisfied, and ends a series of operations at an end step.
• When the SFC program is started, the "initial" step is executed first.
• Execution of the initial step continues until transition condition 0 is satisfied. When this transition condition is satisfied,
execution of the initial step is stopped, and processing proceeds to the step which follows the initial step.
Processing of the SFC program continues from step to step in this manner until the END step has been executed.
1 GENERAL DESCRIPTION
1.1 Description of SFC Program
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