Parallel Transition - Mitsubishi Electric MELSEC-Q Series Programming Manual

Parallel transition

"Parallel transition" is the transition format in which several steps linked in parallel are processed simultaneously when the
relevant transition condition is satisfied.
Item SFC diagram
Branch
Coupling
Up to 32 steps can processed simultaneously with the parallel transition format.
Description
• From step "n", processing will proceed simultaneously to steps
"n+1" and "n+3" when transition condition "b" is satisfied.
• Processing will proceed to step "n+4" when transition condition "c"
is satisfied, and to step "n+4" when transition condition "d" is
satisfied.
• When transition conditions "b" and "c" are satisfied at step "n" and
step "n+1" execution, steps "n" and "n+1" will be deactivated, and
processing will proceed to the waiting steps.
• Waiting steps are used to synchronize parallel processing
operations. Parallel processing steps always proceed to a waiting
step. When condition "d" is satisfied at the waiting steps, processing
will proceed to step "n+2".
• Waiting steps are dummy steps which require no operation output
ladder.
4 SFC PROGRAM CONFIGURATION
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4.3 Transition