Block 0 Start Condition - Mitsubishi Electric MELSEC-Q Series Programming Manual

Block 0 START condition

The block 0 START condition is designed to set whether block 0 will be automatically activated or not at SFC program START
(when SM321 turns from OFF to ON).
Use the block 0 START condition when it is desired to specify the START block at SFC program START according to the
product type, etc.
"Auto START ON" is useful when block 0 is used as described below.
• Used as a control block
• Used as a preprocessing block
• Used as an always watched block
Settings and corresponding operations
Set block 0 to "Auto START ON" or "Auto START OFF".
At SFC program START and END step execution, operations are performed as described below.
Setting
Autostart block 0
(default)
Do not autostart block 0
4 SFC PROGRAM CONFIGURATION
122
4.7 SFC Operation Mode Setting
Operation
At SFC Program START
Block 0 is automatically activated, and is executed from its
initial step.
Block 0 is activated by a START request resulting from an
SFC control "block START" instruction or a block START
step, in the same manner as other blocks.
At end step execution in block 0
When the end step is reached, the initial step is
automatically activated again.
When the end step is reached, block 0 is deactivated and
waits for another START request to be issued again.