Mitsubishi FX3G Series Programming Manual

499
FX3G/FX3U/FX3GC/FX3UC Series
Programming Manual - Basic & Applied Instruction Edition
18 Floating Point – FNC110 to FNC139
18.9 FNC121 – ESUB / Floating Point Subtraction
11
FNC30-FNC39 Rotation and Shift
12
FNC40-FNC49 Data Operation
13
FNC50-FNC59 High-Speed Processing
14
FMC60-FNC69 Handy Instruction
15
FNC70-FNC79 External FX I/O Device
16
FNC80-FNC89 External FX Device
17
FNC100-FNC109 Data Transfer 2
18
FNC110-FNC139 Floating Point
19
FNC140-FNC149 Data Operation 2
20
FNC150-FNC159 Positioning Control
18.9 FNC121 – ESUB / Floating Point Subtraction
Outline
This instruction executes subtraction of two binary floating point data.
→ For program examples of floating point operations, refer to Section 12.10.
→ For handling of floating point, refer to Subsection 5.1.3.
→ For flag operations, refer to Subsection 6.5.2.
1. Instruction format
2. Set data
*1. When a constant (K or H) is specified, it is automatically converted into binary floating point (real number)
when the instruction is executed.
3. Applicable devices
S: This function is supported only in FX3U/FX3UC PLCs.
Explanation of function and operation
1. 32-bit operation (DESUB and DESUBP)
Binary floating point data [ +1, ] is subtracted from binary floating point data [ +1, ], and the
subtraction result in the binary floating point format is transferred to [ +1, ].
When a constant (K or H) is specified as [ +1, ] or [ +1, ], it is automatically converted into
binary floating point.
Caution
1. When the same device is specified
The same device number can be specified in [ +1, ],[ +1, ] and [ +1, ].
In this case, note that the subtraction result changes in every operation cycle when the continuous operation type
instruction (DESUB) is used.
Operand Type Description Data Type
Word device number storing binary floating point data used in subtraction
Real number (binary)
*1
Word device number storing binary floating point data used in subtraction
Data register number storing the subtraction result
Oper-
and
Type
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
33 S 333 3
33 S 333 3
33 S 3
P
FNC 121
ESUB
D
−
Mnemonic Operation Condition
16-bit Instruction
DESUB
DESUBP
Mnemonic Operation Condition
32-bit Instruction
13 steps
Continuous
Operation
Pulse (Single)
Operation
S 1
S 2
D
S 1
S 2
D
S 2 S 2 S 1 S 1
D D
FNC121
DESUB
Command
input
S 1  S 2  D 
[ +1, ] − [ +1, ] → [ +1, ]
Binary floating point Binary floating point Binary floating point
S 1  S 1  S 2  S 2  D  D 
S 1 S 1 S 2 S 2
FNC121
DESUB
Command
input
S 1  S 2  D 
[ +1, ] − [ K2346 ] → [ +1, ]
Binary floating point Automatically
converted into binary
floating point
Binary floating point
S 1  S 1  D  D 
S 1 S 1 S 2 S 2 D D

Mitsubishi FX3G Series Specifications

General

Model	FX3G Series
Power Supply	AC 100-240V or DC 24V
Program Capacity	32, 000 steps
Execution Speed	0.21 µs/basic instruction
Communication Options	RS-422, USB, Ethernet
Expansion Modules	Analog, digital, communication
Programming Language	Ladder Logic, Instruction List
Built-in Functions	High-speed counters, pulse output
Analog I/O	Available via expansion modules