Block Start Step (With End Check) - Mitsubishi Electric MELSEC-Q Series Programming Manual

Block START step (with END check)

A block START step (with END check) is the step where the specified block is started, and when the START destination block
is then deactivated, the check of the transition condition to the next step is started.
The operation of the block START step (with END check) is described below.
• When activated, the block START step (with END check) starts the specified block.
• No processing is performed until the START destination block is deactivated after its execution has ended.
• When the START destination block is deactivated after its execution has ended, only the transition condition check is
performed.
• When the transition condition is satisfied, a transition to the next step occurs.
Start for a single block
A simultaneous start cannot be made for a single block. The block that has already started cannot be started, either. If either
of the above starts is made, the following processing is performed depending on the setting of the operation mode at block
double START.
■When the setting of the operation mode at block double START is "STOP"
A "BLOCK EXE. ERROR" (error code: 4620) occurs and the CPU module stops processing.
■When the setting of the operation mode at block double START is the default setting of
"WAIT"
Processing is not performed and waits until the START destination block ends its execution.
For the following CPU modules, the operation mode at double block START cannot be set. The operation
mode at double block START is limited to the "WAIT" mode.
• Basic model QCPU
• Q00UJCPU, Q00UCPU, Q01UCPU, Q02UCP
• Universal model QCPU whose serial number (first five digits) is "12051" or earlier
• LCPU
Block START request
A block START request can start multiple blocks simultaneously by performing a parallel transition The steps in the
simultaneously started blocks are processed in parallel.
4 SFC PROGRAM CONFIGURATION
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4.2 Steps