Step Transition Bit - Mitsubishi Electric MELSEC-Q Series Programming Manual

Step transition bit

The step transition bit is designed to check whether the transition condition of the step in execution has been satisfied or not.
• After the operation output at each step is completed, the step transition bit automatically switches ON when the transition
condition (for transition to the next step) is satisfied.
• A transition bit which is ON will automatically switch OFF when processing of the block in question occurs again.
Ex.
Step transition bit = M1
• If a continuous transition is designated (continuous transition bit ON), the transition bit will remain ON during the next step's
operation output after the transition condition is satisfied. It will also remain ON following the execution of multiple steps,
even if the transition condition is unsatisfied. In these cases, the transition bit will switch OFF when block execution occurs
at the next scan.
Ex.
Step transition bit = M1
4 SFC PROGRAM CONFIGURATION
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4.5 SFC Information Devices