Mitsubishi Electric MELSEC iQ-F Series - Page 79

8 SFC PROGRAM
8.2 Structure
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8
Step types
The following table lists the types of steps.
The following table lists the attributes of steps.
• The type of a step can be changed by changing the setting of "Step Attribute" in the "Step Properties"
window.
• For the reset step [R], block start step (with END check) [BC], or block start step (without END check) [BS],
specify a step name or a block No. in "Step Attribute Target" in the Properties window.
For the setting procedure, refer to the following.
GX Works3 Operating Manual
Item Description
Initial step A step that indicates the beginning of a block.
While this type of step is active, the transition following the
step is constantly checked, and when the transition becomes
TRUE, the next step becomes active.
The attributes of SC and R can be added. This step can also
be used as a step without creation of an action.
Normal step A basic step used to configure a block.
While this type of step is active, the transition following the
step is constantly checked, and when the transition becomes
TRUE, the next step becomes active.
The attributes of SC, R, BC, and BS can be added. This step
can also be used as a step without creation of an action.
End step A step that ends a block.
An action cannot be created.
Attribute Item Description
SC Coil HOLD step [SC] Coil HOLD step [SC] is a step that holds the outputs of a coil
that has been turned on by the action even after the active
state transitions.
R Reset step [R] Reset step [R] is a step that deactivates the specified step.
BC Block start step (with
END check) [BC]
A step that activates the specified block.
When the specified block becomes inactive and the transition
becomes TRUE, the active state transitions to the next step.
An action cannot be created.
BS Block start step (without
END check) [BS]
A step that activates the specified block.
When the transition becomes TRUE, the active state
transitions to the next step.
An action cannot be created.
N Action0
Initial S0
Initial S0
N Action1
Step0 S1
Step0 S1
EndStep
N Action2
Step1
SC
S2
N Action3
Step2
R
S3
Step1
Step3
BC
S4
BL1
Step4
BS
S5
BL2