End - Mitsubishi Electric MELSEC FX3U Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
7.15

END

Outline
END instruction specifies the end of a program.
(Do not write the END instruction in the middle of a program.)
1. Instruction format
END
END
2. Applicable devices
Bit Devices
Instruc-
System User
tion
X Y M T C S D .b KnX KnY KnM KnS T C D R U \G
END
Explanation of function and operation
1. END instruction (program end, I/O refresh and return to step 0)
PLCs repeat "input processing → program execution → output processing". When END instruction is written
at the end of a program, PLCs immediately execute the output processing without executing steps after END
instruction.
If END instruction is not written at the end of a program, PLCs execute the program until the final step, and
then execute the output processing.
At the first execution after the PLC mode was changed from STOP to RUN, PLCs start from END instruction.
When END instruction is executed, the watchdog timer (which checks the operation cycle) is refreshed.
Caution
Do not write END instruction in the middle of a program.
When a program is transferred from a programming tool, all steps after END instruction are replaced with
NOP (no operation) instructions.
Mnemonic Operation Condition
Basic Instruction
END
1 step
−
Word Devices
Digit Specification
There are no applicable devices.
Input processing
Step 000
LD
001
002
OUT
END
NOP
NOP
NOP
Output processing
Continuous
Operation
Pulse (Single)
Operation
Special
System User Index
Unit
V Z Modify K H
X000
Y000
7 Basic Instruction
7.15 END
Others
Con- Real Charac-
Pointer
stant Number ter String
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