Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 103

End step
End step is a step that ends a block.
• When the active state transitions to the end step and no active step exists other than steps that hold operations in the block,
all the HOLD steps [SC, SE, ST] that hold operations in the block are deactivated and the block is ended.
• When a block contains any active steps other than steps that hold operations in a block, the following processing is
performed depending on the status of SM328 (Clear processing mode when the sequence reaches the end step).
Status of SM328
Off (default)
On
• When clear processing is performed, the coil outputs turned on by using the OUT instruction are all turned off. However, for
the coil output of the HOLD steps [SC, SE, ST] that hold operations, the following processing is performed depending on
the status of SM327 (Output mode at execution of the end step).
Status of SM327
Off (default)
On
• The following shows how to restart the block once ended.
Item
Block 0 The start condition of block 0 is set to
"Auto-start block 0" in the SFC setting
of parameters.
The start condition of block 0 is set to
"Do not auto-start block 0" in the SFC
setting of parameters.
All blocks other than block 0
■ Precautions
• An action cannot be created to the end step.
• The setting of SM327 (Output mode at execution of the end step) is valid only when the end step becomes active. When a
forced termination is performed such as by using the RST instruction (Ending a block), the coil outputs of all steps are
turned off.
• If the HOLD steps [SC, SE, ST] holding operations remain when the end step becomes active, those steps [SC, SE, ST] are
deactivated even though SM328 (Clear processing mode when the sequence reaches the end step) is on. If turning off the
coil outputs of the HOLD steps [SC, SE, ST] that hold operations is not required, turn on SM327. The following figure shows
the operational relationships between SM328 and HOLD steps [SC, SE, ST].
Description
Clear processing is performed.
The active steps remaining in the block are all terminated forcibly to end the block.
Clear processing is not performed.
The execution of the block is continued as is and the block is not ended.
Description
All the HOLD steps [SC, SE, ST] that hold operations are turned off.
All the outputs of the HOLD steps [SC, SE, ST] that hold operations are held.
The setting of SM327 is valid for only the HOLD steps [SC, SE, ST] that hold operation. All the outputs
of the HOLD steps [SC, SE, ST] that do not hold operations and the transition does not become TRUE
are turned off. Also, when SM327 is on, the steps become inactive.
However, when a forced end is performed such as by the block end instruction, the coil outputs of all
steps are turned off.
Description
The initial step is automatically activated again and processing is executed repeatedly.
The block is restarted when a start request is issued for the specified block in the following methods.
• The block start step is activated by another block.
• The SET (Starting a block) instruction is executed.
• The block START/END bit of the SFC information device is turned on.
8 SFC PROGRAM
101
8.2 Structure
8