FX
3G
/FX
3U
/FX
3UC
PLC User's Manual - Positioning Control Edition
Built-in Positioning Functions
4 Before Programming
4.10 Format and Execution of Applied Instruction
B - 77
A
Common Items
B
Built-in
Positioning
Functions
Apx.
Example
Connection
Format and execution of instruction:
Depending on the sizes of the numeric values to be processed, applied instructions can be classified into two
types: 16-bit instructions and 32-bit instructions. In addition, depending on the execution type, these
instructions can also be classified into two types: continuous execution type and pulse execution type.
Depending on the applied instruction, the instruction may or may not have all the combinations.
1. 16-bit instructions and 32-bit instructions
- Depending on the bit length of the numeric data to be processed, applied instructions can be classified
into two types: 16-bit type and 32-bit type.
Move D10 to D12.
This instruction transfers data from D21 and D20 to D23
and D22.
- For the 32-bit instruction, the instruction name will be DMOV ("D" will be added to "MOV").
- Even numbered devices or odd numbered devices can be specified. If a double device is specified, the
specified device will be combined with the device with the next number (for the word devices, such as
devices T, C, and D).
To prevent confusion, it is recommended to use even numbered devices to specify the low-order bits of
an operand of a 32-bit instruction.
- Each 32-bit counter (C200 to C255) needs only one device to set 32 bits. For this reason, the operand
of a 16-bit instruction cannot specify any of the 32-bit counters.
2. Pulse execution type instructions and continuous execution type instructions
Pulse execution type instructions:
The program shown in the right figure shows that when X000 is
turned on, the instruction will be executed only once. If X000 is
off, the instruction will not be executed. If it is not necessary to
execute the instruction frequently, the pulse execution type
instruction is recommended. Note that "P" means that the
instruction of pulse execution type. This means that DMOVP is a
pulse execution type instruction.
Continuous execution type instructions:
The program shown in the right figure shows that if X001 is on,
the continuous execution type MOV instruction will be executed
at the start of each operation cycle.
Note that if FNC24 (INC) or FNC25 (DEC) is used as a continuous execution type instruction, the
destination will be changed at the start of each operation cycle.
To indicate continuous execution type instructions, the symbol " " will be added to the title of each
instruction as shown in the following figure. Use these instructions carefully.
Note that if the activation input X000 or X001 is off, instructions will not be executed. Also note that if the
later symbol is not added to the title of an instruction, the destination of the instruction will not be changed.
Command 1
FNC 12
MOV
D10 D12
Command 2
FNC 12
DMOV
D20 D22
X000
FNC 12
MOVP
D10 D12
X001
FNC 12
MOV
D10 D12
P
FNC 12
MOV
Number
Instruction name
D
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