Mitsubishi MELSEC-Q/L User Manual

88
3.2.4 Using real number data
Real number data is floating decimal point data used with basic instructions and application instructions.
Only word devices are capable of storing real number data.
(1) Single-precision floating-point data
Instructions which deal with single-precision floating-point data designate devices which are used for the lower 16 bits of
data.
Single-precision floating-point data are stored in the 32 bits which make up (designated device number) and (designated
device number + 1).
Remark
In sequence programs, floating decimal point data are designated by E .
Single-precision floating-point data uses two word devices and is expressed in the following manner:
[Sign] 1. [Mantissa part] 2
[Exponent part]
The bit configuration and meaning of the internal representation of single-precision floating-point data is as
follows:
• Sign The sign is represented at b31.
0: Positive
1: Negative
• Exponent part The n of 2n is represented from b23 to b30.
Depending on the BIN value of b23 to b30, the value of n is as follows:
• Variable part The 23 bits from b0 to b22, represents the XXXXXX... at binary 1.XXXXXX....
(2) Double-precision floating-point data
Instructions which deal with double-precision floating-point datadesignate devices which are used for the lower 16 bits of
data.
Double-precision floating-point data are stored in the 64 bits which make up (designated device number) to (designated
device number + 3).
Designation of 2 points of R100 and R101 (32 bits)
M0
EMOV R100
D0
Designation of 2 points of word devices D0 and D1
(32 bits)
Single-precision floating-point data transfer instruction
b31 b30
to
b23 b22 b16
to
b15b0
to
b31
Sign
b23 to b30
Exponent part
b0 to b22
Mantissa part
b23 to b30 FFH FEH FDH 81 80 7FH 7EH 02 01 00
n
Not used 127
126
2
1 0 -1
-125
-126
Not used
Designation of 4 points of R100, R101, R102 and
R103 (64 bits)
M0
EDMOV R100 D0
Designation of 4 points of word devices D0, D1, D2
and D3 (64 bits)
Double-precision floating-point data transfer
instruction

Mitsubishi MELSEC-Q/L Specifications

General

Brand	Mitsubishi
Model	MELSEC-Q/L
Category	Controller
Language	English