Block End Methods - Mitsubishi Electric MELSEC-Q Series Programming Manual

Block END methods

The methods for ending block operations are described below. As shown below, there are several block END methods.
Choose the method which is most suitable for the purpose at hand.
END Method
Block END by SFC diagram symbol
Block END by SFC control instruction
Block END by SFC information device
*1 Block processing is also ended when the rBLm\Sn instruction is used to deactivate all steps at a specified block.
A forced end to block processing is possible using a method which is different from that used to start the
block.
• A block started by an SFC diagram symbol can be ended by an SFC control instruction (rBLm).
• A block started by an SFC control instruction (sBLm) can be ended by forcibly turning OFF the block
START/END bit of the SFC information devices.
Restart after block END processing is completed
After block END processing is completed, the block can be restarted as shown below.
Block
Block 0 When the Start conditions is designated as "Autostart
block 0"
When the Start conditions is designated as "Do not
autostart block 0"
Other than block 0
Operation Description
Block processing is ended and the block is deactivated
when the block's END step is executed.
Using an SFC control instruction, a specified block is
forcibly ended and deactivated from an SFC program
step (operation output), or from another sequence
*1
program.
The processing of the corresponding block is ended to
deactivate it by forcibly turning OFF the "block START/
END bit", which was set to each block as the SFC
information device, in the program or peripheral device.
Description
After block processing is ended, processing is started automatically from the initial step.
After block processing is ended, the block remains inactive until a START request
occurs by one of the methods. ( Page 160 Block START methods)
Remarks
• Convenient for cycle stops at automatic operations, etc.
• Multiple END steps are possible within a single block.
Convenient for executing a forced STOP (at emergency
stops, etc.) without regard to the operation status.
Convenient for debugging and test operations because
block processing can be ended from a peripheral device
without requiring a program.
6 SFC PROGRAM EXECUTION
6.2 Block START and END
6
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