Instruction Configuration - Mitsubishi Electric MELSEC iQ-R Series Programming Manual

1
OVERVIEW
1.1

Instruction Configuration

Many instructions available for programmable controllers are each divided into the instruction part and device part.
The instruction part and device part are used as follows.
• Instruction part: Indicates the function of the relevant instruction.
• Device part: Indicates the data used for the instruction.
The device part is further classified to source data, destination data, and numerical data.
Source (s)
Source is the data used in the operation.
Depending on the label or device specified in each instruction, the source becomes as follows.
Type
Constant
Bit device
Word device
*1 For the index modification, refer to the following.
 MELSEC iQ-R CPU Module User's Manual (Application)
Destination (d)
Data after operation is stored in the destination area.
However, some instructions require the data to be used in the operation to be stored before the operation.
Ex.
Binary 16-bit data addition instruction
+ s
(1) The data required for operation is stored before the operation.
(2) Only the operation result is stored.
A label or device to store data must be set for the destination.
1 OVERVIEW
34
1.1 Instruction Configuration
Description
The constant specifies a numerical value used in the operation.
It is set during program creation and cannot be changed during program execution.
When using constants in variable data, perform index modification.
The user specifies the device where the data to be used in the operation is stored.
Necessary data must be thus stored in the specified device before operation execution.
By changing the data to be stored in the specified device during program execution, the data to be used by the
instruction can be changed.
d +
(1)
s1 s2 d
(2)
*1