Active Step Change Instruction (Schg) - Mitsubishi MELSEC-Q Series Programming Manual

4 SFC PROGRAM CONFIGURATION

4.4.10 Active step change instruction (SCHG)

Internal Device
File
(System, User)
Register
R
Bit Word
D
[Function]
(1) Deactivates the step that executed an instruction, and forcibly activates the specified step (set
with the device designated by
(2) When the destination step is already active, the step that executed the SCHG instruction is
deactivated and the destination step continues processing as-is.
(3) The step where this instruction is executed is deactivated when processing proceeds to the
transition condition status check following the completion of that step's program operation.
(4) This instruction can only be used at SFC program steps.
[Operation Error]
• Error No.4631 occurs when the specified destination step does not exist.
• Error No.4001 occurs when this instruction is used at a sequence program other than an
SFC program (error is activated on switching from STOP to RUN).
[Program Examples]
(1) When X1 switches ON, the following program deactivates step 5, and activates step 6.
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Usable Devices
Link Direct
Intelligent
J
\ Function Index
Module Z
Bit Word
U \G
SCHG
D
S5
Data
Expansion
Type
Constant Other
SFC
BIN16
) in the same block.
D
S6
X1
Programs Using Instructions
SFC Program
Sequence
Block Step
Program
Transition
Step
Condition
SCHG K6
Execution Site
Transition
Condition
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