Mitsubishi Electric MELSEC-Q/L - Operation When the OUT, SET;RST, or PLS;PLF Instructions Use the same Device

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3 CONFIGURATION OF INSTRUCTIONS
3.9 Operation When the OUT, SET/RST, or PLS/PLF Instructions Use the Same Device
3.9 Operation When the OUT, SET/RST, or PLS/PLF
Instructions Use the Same Device
The following describes the operation for executing multiple instructions of the OUT, SET/RST, or PLS/PLF that use the same
device in one scan.
OUT instructions using the same device
Do not program more than one OUT instruction using the same device in one scan. If the OUT instructions using the same
device are programmed in one scan, the specified device will turn ON or OFF every time the OUT instruction is executed,
depending on the operation result of the program up to the relevant OUT instruction. Since turning ON or OFF of the device is
determined when each OUT instruction is executed, the device may turn ON and OFF repeatedly during one scan. The
following diagram shows an example of a ladder that turns the same internal relay (M0) with inputs X0 and X1 ON and OFF.
With the refresh type CPU module, when the output (Y) is specified by the OUT instruction, the ON/OFF status of the last
OUT instruction of the scan will be output.
[Ladder]
[Timing Chart]
M0
X0
M0
X1
M0
M0
M0
M0
OFF
ON
ON
OFF
ON
END
END END
X0
X1
M0
X0
X0
X1 X1
OFF
M0 turns ON because X0 is ON.
M0 turns OFF because X1 is OFF.
M0 remains OFF because X0 is OFF.
M0 turns ON because X1 is ON.