Instruction Structure - Mitsubishi MELSEC-A Series Programming Manual

3. INSTRUCTION STRUCTURE

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
Example: END, FEND
b) Instruction part + device .... Switches the device on/off, controls the
Example: LD X0
c) Instruction part + Source device + Destination device
Example:
d) Instruction part + Source 1 device
+ Source 2 device + Destination device
Example:
e) Others ....... Combination of a) to d).
program.
execution condition in accordance with the
device status, branches the program, etc.
Device
Instruction part
..... Operation is performed using the
Destination device
Source device
Instruction part
Destination device
Source 2 device
Source 1 device
Instruction part.
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MELSEC-A
destination data and source data,
and the operation result is stored
to the destination.
...... Operation is performed
using the source 1 data
and source 2 data, and the
operation result is stored
to the destination.