Mitsubishi MELSEC-A series Programming Manual

3. INSTRUCTION STRUCTURE
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MELSEC-A
3. INSTRUCTION STRUCTURE
3.1 Instruction Structure
1) Many instructions may be divided into an instruction part and a device as
follows:
Instruction part…….. Indicates the function.
Device……………… Indicates the data for use with that instruction.
2) The instruction structure may be largely classified as follows with the
instruction part and device(s) combined:
a) Instruction part ……. Retains the device status and mainly controls the
program.
Example: END, FEND
b) Instruction part + device …. Switches the device on/off, controls the
execution condition in accordance with the
device status, branches the program, etc.
c) Instruction part + Source device + Destination device
….. Operation is performed using the
destination data and source data,
and the operation result is stored
to the destination.
d) Instruction part + Source 1 device
+ Source 2 device + Destination device
…… Operation is performed
using the source 1 data
and source 2 data, and the
operation result is stored
to the destination.
e) Others ..….. Combination of a) to d).
Example: LD X0
Device
Instruction part
Example:
Destination device
Source device
Instruction part
Destination device
Source 2 device
Source 1 device
Instruction part.
Example:

Mitsubishi MELSEC-A series Specifications

General

Brand	Mitsubishi
Model	MELSEC-A series
Category	Controller
Language	English