Mitsubishi Electric M800VW Series Programming Manual page 125

M800V/M80V Series PLC Programming Manual (1/2)
6 Explanation of Instructions and Functions
6.3 Data Designation Method
 Double-precision real number (double-precision floating-point data)
To designate devices for instructions using double-precision floating-point data, lower 16 bits will be used.
Double-precision floating-point data is stored in 64 bits composed of "designated device number" and "designated device
number + 3".
M0
EDMOV R100 D0
In a sequence program, floating-point data is designated by E ○ .
Double-precision floating-point data is represented as follows, using four word devices.
[Exponent]
[Sign] 1.[Mantissa] × 2
The bit configuration and meaning for the internal representation of double-precision floating-point data are described below:
b63 b62 to b52 b51
b63 b52 to b62
Sign Exponent
 Sign: b63 shows the sign.
0: Positive
1: Negative
 Exponent: b52 to b62 show n of 2n. As shown in the following, n corresponds to the BIN values of b52 to b62.
b52 to b62 7FFH 7FEH
n Not used 1023
 Mantissa: 52 bits from b0 to b51 show the value of "XXXXXX..." when the data is "1.XXXXXX..." in binary.
IB-1501667-B
Designation of 4 points of word devices D0, D1, D2 and D3 (64 bits)
Designation of 4 points of word devices R100, R101, R102 and
R103 (64 bits)
Double-precision floating-point data transfer instruction
to b16 b15 to
b0 to b51
Mantissa
7FDH 400H 3FFH
1022 1
0
104
b0
3FEH 3FDH 3FCH
1 -2 -3
02H 01H 00H
-1021 -1022
Not used