Mitsubishi Electric MELSEC FX Series - Page 471

7 Applied Instructions
7.12 Floating Point
469
FXCPU Structured Programming Manual
(Basic & Applied Instruction)
1
Outline
2
Instruction List
3
Configuration of Instruction
4
How to Read Explanation of Instructions
5
Basic Instruction
6
Step Ladder Instructions
7
Applied Instructions
8
Interrupt Function and Pulse Catch Function
A
Relationships between devices and addresses
Function and operation explanation
1. 32-bit operation (DEBCD, DEBCDP)
The binary floating decimal point of the device specified by is converted into decimal floating decimal
point, and is transferred to the device specified by .
Cautions
1) In the floating decimal point operation, all operations are executed at the binary floating decimal point.
However, since the binary floating decimal point is a difficult numeric value (exclusive monitor method),
by converting it into decimal floating decimal point, it is easier for monitoring by peripheral devices or the
like.
Meanwhile, GX Works 2 or GOT is provided with a function for monitoring or displaying the binary floating
decimal point directly.
2) When handling 32-bit data in structured program, you cannot specify 16-bit device directly unlike the
simple project. When handling 32-bit data, please use the label.
However, the 32-bit counter is a 32-bit long device, and can be specified directly. When specifying the
device, use the global label.
3) Applicable devices are limited.
S: FX
3U, FX3UC PLCs only are applicable.
Command
input
Binary floating
decimal point
Decimal floating
decimal point
[ +1, ] → [ +1, ]
DEBCD
EN ENO
d
s
ds s d
Label 1
*1
Label 2
*2
*1. To define the device for storing the binary
*2. To define the device for storing the converted
floating decimal point data.
decimal floating decimal point data.
After execution
Higher position Lower position
b15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0b31 b30 b29 b28 b27 b26 b25 b24 b23 b22 b21 b20 b19 b18 b17 b16
Before
execution
Mantissa part (23 bits)
+1
Lower position
b15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
Higher position
b31 b30 b29 b28 b27 b26 b25 b24 b23 b22 b21 b20 b19 b18 b17 b16
After
execution
Mantissa partExponential part
+1
×10
+1
Exponential part (8 bits)
Sign (1 bit)
d
s
d
s
d
d