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FX3G/FX3U/FX3UC Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
7 Basic Instruction
7.14 NOP
1
Introduction
2
Overview
3
Instruction
List
4
Devices
in Detail
5
Specified the
Device &
Constant
6
Before
Programming
7
Basic
Instruction
8
FNC00-FNC09
Program Flow
9
FNC10-FNC19
Move & Compare
10
FNC20-FNC29
Arith. & Logic
Operation
7.14 NOP
Outline
NOP instruction specifies no operation.
When a program is erased completely, all steps are replaced with NOP instructions.
When NOP instruction is located between general instructions, PLCs ignore NOP instruction.
If NOP instructions are put in the middle of a program, fluctuation of step numbers is minimized when the program is
changed or added. But excessive program steps are required.
Note that circuits are considerably changed if already written instructions are replaced with NOP instructions.
1. Instruction format
2. Applicable devices
Explanation of function and operation
1. NOP instruction (no operation or null step)
NOP instruction specifies no operation.
If NOP operation is written in the middle of a program, PLCs ignore it in executing the program.
When an existing program is replaced with NOP instructions, it means that former instructions are deleted.
Instruc-
tion
Bit Devices Word Devices Others
System User Digit Specification System User
Special
Unit
Index
Con-
stant
Real
Number
Charac-
ter String
Pointer
XYMTCSD.b KnX KnY KnM KnS T C D R U\G VZModifyKH E ""P
NOP There are no applicable devices.
NOP
No Operation
Basic Instruction
NOP
−
Continuous
Operation
Pulse (Single)
Operation
Mnemonic Operation Condition
1 step
AND
→
NOP ANI
→
NOP
Contact becomes
short-circuit.
OR
→
NOP
Circuit is
disconnected.
ORI
→
NOP
OUT
→
NOP (error)