Continuous Transition On/Off Operation - Mitsubishi Electric MELSEC-Q Series Programming Manual

Continuous transition ON/OFF operation

There are two types of SFC program transition processing: "with continuous transition" and "without continuous transition".
Set "with continuous transition" or "without continuous transition" using the continuous transition bit of the SFC information
devices. When the device set to the continuous transition bit is turned ON/OFF by the user, operation is performed as
described below.
Continuous SM323
Transition Bit
No setting OFF
ON
OFF ON/OFF
ON ON/OFF
The tact time can be shortened by setting "with continuous transition". This resolves the problem of waiting
time from when the transition condition is satisfied until the operation output of the transition destination step
is executed. However, when "with continuous transition" is set, the operations of the other blocks and
sequence program may become slower.
Transition processing for continuous transition OFF setting
The SFC program processing procedure without continuous transition will be explained.
5 SFC PROGRAM PROCESSING SEQUENCE
156
5.3 SFC Program Processing Sequence
Operation
Without continuous When the transition condition is satisfied, the operation output of the transition destination
transition step is executed in the next scan.
With continuous When the transition condition is satisfied, the operation output of the transition destination
transition step is executed within the same scan. When the transition conditions of the steps are
satisfied continuously, the operation outputs are executed within the same scan until the
transition condition is not satisfied or the end step is reached.
Without continuous When the transition condition is satisfied, the operation output of the transition destination
transition step is executed in the next scan.
With continuous When the transition condition is satisfied, the operation output of the transition destination
transition step is executed within the same scan. When the transition conditions of the steps are
satisfied continuously, the operation outputs are executed within the same scan until the
transition condition is not satisfied or the end step is reached.