Execution Type Designation By Instructions - Mitsubishi Electric MELSEC-Q Series Programming Manual

Execution type designation by instructions

The "execution designation by instruction" function enables the execution type set in the program setting of the PLC
parameter dialog box to be changed by the instruction. This function can be applied to normal SFC programs only.
(Inapplicable to the SFC programs for program execution management.)
Instructions and corresponding operations
The following shows instructions and corresponding operations.
: Compatible, : Incompatible
Instruction Operation
PSTOP Switches the program of the specified file name to a stand-by status, beginning in the next scan.
POFF Executes the end processing of all blocks in the next scan in the SFC program of the specified file name, and
switches the program to a stand-by status in the second scan after execution of the instruction.
PSCAN • Switches the program of the specified file name to a scan execution type, beginning in the next scan.
• The execution order of multiple programs changes depending on the program setting order in the PLC
PLOW • Switches the program of the specified file name to a low-speed execution type, beginning in the next scan.
• The execution order of multiple programs changes depending on the program setting order in the PLC
The following conditions will result in an operation error:
• When the specified program does not exist. (error No. 2410).
• When the PSTOP or PLOW instruction is executed (error No. 2412)
• When an scan execution type SFC program already exists when changing another SFC program to a scan
execution type using the PSCAN instruction. (error No.2504)
• The scan execution status of the specified SFC program can be checked using the PCHK instruction. (For
the Basic model QCPU, Universal model QCPU, and LCPU, the PCHK instruction is not available.) For
details on the PCHK instruction, refer to the Programming Manual (Common Instructions) for the CPU
module used.
Instruction format
The following shows how to create an instruction.
5 SFC PROGRAM PROCESSING SEQUENCE
148
5.2 Whole Program Processing of High Performance Model QCPU, Process CPU, Redundant CPU, Universal Model QCPU, and
parameter dialog box.
parameter dialog box.
SFC
Compatibility



