Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 96

Step types
The following table lists the types of steps.
Item
Initial step
Normal step
End step
The following table lists the attributes of steps.
Attribute Item
SC Coil HOLD step [SC]
SE Operation HOLD step (without
transition check) [SE]
ST Operation HOLD step (with
transition check) [ST]
R Reset step [R]
BC Block start step (with END
check) [BC]
BS Block start step (without END
check) [BS]
• The type of a step can be changed by changing the setting of "Type" 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 "Attribute Target" in the property window.
For the setting method, refer to the following.
 GX Works3 Operating Manual
8 SFC PROGRAM
94
8.2 Structure
Description
A step that indicates the beginning of a block.
While this type of step is active, the transition following the step is
always checked, and when the transition becomes TRUE, the next
step becomes active.
Attributes of SC, SE, ST, and R can be added.
This step can also be used as a step without an action.
A basic step used to comprise a block.
While this type of step is active, the transition following the step is
always checked, and when the transition becomes TRUE, the next
step becomes active.
Attributes of SC, SE, ST, R, BC, and BS can be added.
This step can also be used as a step without an action.
A step that ends a block.
An action cannot be created.
Description
A step that holds the outputs of a coil that has been turned on by
the action even after the active state transitions.
A step which continues the operation of the action even after the
active state transitions.
After the transition becomes TRUE and the next step is activated,
the transition is not checked.
A step which continues the operation of the action even after the
active state transitions.
Even after the transition becomes TRUE and the next step is
activated the transition is checked repeatedly.
A step that deactivates the specified step.
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.
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.