Operation Mode At Transition To Active Step (Double Step Start) - Mitsubishi Electric MELSEC-Q Series Programming Manual

Operation mode at transition to active step (double step START)

This mode setting designates the operation mode which is to be effective when a follow-up function such as an operation
HOLD step (with transition check) is used to execute a transition to a step which is already active.
Settings and corresponding operations
For a transition to an active step, set any of STOP, WAIT and TRANSFER in the "block parameter" of the FC setting dialog
box in the Tools menu.
The operations resulting from these settings are shown below.
Setting Operation
STOP • A CPU module operation error (BLOCK EXE.ERROR) occurs, and CPU module
operation is stopped.
• All "Y" outputs switch OFF.
WAIT • CPU module operation continues, and a WAIT status is established when the
transition condition is satisfied. The WAIT status continues until the START
destination step is deactivated.
• If a transition WAIT occurs, the previous step is deactivated, the output is switched
OFF, and the operation output will not be executed.
TRANSFER • CPU module operation continues, the transition occurs, and the previous step is
(default) deactivated and absorbed by the transition destination step.
Transition to HOLD step by double START
The following table shows the transition procedure for transitions to coil HOLD steps, operation HOLD steps (with transition
check), and operation HOLD steps (without transition check) which occur when the double START condition is satisfied.
These transitions occur without regard to the settings described at item (1) above.
Setting Operation
STOP • The TRANSFER setting applies to all operations, regardless of the setting.
WAIT • At coil HOLD steps
TRANSFER (default) The operation output is restarted, and a transition condition check begins.
The PLS instruction for which the input conditions have already been established is
non-executable until the input conditions are turned on again.
• At operation HOLD steps (without transition check)
A transition condition check begins.
• At operation HOLD steps (with transition check)
Operation continues as is.
Remarks
A step range can be designated for the
STOP setting.
A step range can be designated for the
WAIT setting.
Remarks
Following the double START, execution of
all subsequent steps where transition
conditions are satisfied will occur according
to the step attributes.
4 SFC PROGRAM CONFIGURATION
4.7 SFC Operation Mode Setting
4
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