Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 28

Precautions
■When setting an input value of single-precision real number from the engineering tool
The number of significant digits is about 7 because the engineering tool processes single precision real number data in 32-bit
single precision.
When the input value of single-precision real number data exceeds 7 digits, the 8th digit is rounded off.
Therefore, if the rounded-off value goes out of the range from -2147483648 to 2147483647, it will not be an intended value.
Ex.
When "2147483647" is set as an input value, it is handled as "2147484000" because 8th digit "6" is rounded off.
Ex.
When "E1.1754943562" is set as an input value, it is handled as "E1.175494" because 8th digit "3" is rounded off.
Set an input value within the following range. If the set value is out of the following range, a conversion error occurs.
Decimal point expression: 0.0000000001 ≤ Absolute value of real number data ≤ 999999900000.0
Exponential notation: 1.175494351E-38 ≤ Absolute value of real number data ≤ 3.402823466E+38
■When setting an input value of double-precision real number from the engineering tool
The number of significant digits is about 15 because the engineering tool processes double precision real number data in 64-
bit double precision.
When the input value of double-precision real number data exceeds 15 digits, the 16th digit is rounded off.
Therefore, if the rounded-off value goes out of the range from -2147483648 to 2147483647, it will not be an intended value.
Ex.
When "2147483646.12345678" is set as an input value, it is handled as "2147483646.12346" because 16th digit "6" is
rounded off.
Ex.
When "E1.7976931348623157+307" is set as an input value, it is handled as "E1.79769313486232+307" because 16th digit
"5" is rounded off.
Set an input value within the following range. If the set value is out of the following range, a conversion error occurs.
Decimal point expression: 0.00000000000000000001 ≤ Absolute value of real number data ≤ 999999999999999000000.0
Exponential notation: 2.22507385850721E-308 ≤ Absolute value of real number data ≤ 1.79769313486231E+308
The monitor function of the engineering tool can monitor real number data of motion systems.
To represent "0" in real number data, set all numbers in each of the following range to 0.
• Single-precision real number data: b0 to b31
• Double-precision real number data: b0 to b63
The setting range of real number data is as follows. For the operations to be performed when an overflow or
underflow occurs or when a special value is input, refer to the following.
• Single-precision real number data: -2
precision real number data]<2
• Double-precision real number data: -2
precision real number data]<2
1 OVERVIEW
26
1.2 Data Specification Method
128
<[single-precision real number data]≤-2
128
1024
<[double-precision real number data]≤-2
1024
-126 -126
, 0, 2
≤[single-
-1022 -1022
, 0, 2
≤[double-