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9.13.3 Real number (E)
(1) Definition
The real number (E) is a device used to specify real numbers in sequence programs.
In sequence programs, specify it as E
(example: E1.234). (
(2) Specification range
(a) Real number setting range
• For single-precision floating-point data
-2
128
< Device -2
-126
, 0, 2
-126
Device < 2
128
• For double-precision floating-point data
-2
1024
< Device -2
-1022
, 0, 2
-1022
Device < 2
1024
(b) When an overflow or underflow has occurred
Table9.12 shows the operation of the CPU module when an overflow or underflow has occurred during
arithmetic operation.
arithmetic operation.
(c) When a special value
*1
is input
If operation is performed with input data that contains a special value, "OPERATION ERROR" (error code:
4140) occurs.
4140) occurs.
*1: The special values are -0, unnormalized numbers, nonnumeric characters, and
.
(3) Specification method
Real numbers can be specified in sequence programs by the following expressions.
• Normal expression ••• A numeric value can be specified as it is.
10.2345 can be specified as E10.2345.
• Exponential expression ••• A numeric value is specified by (Value)
10
n
.
1234 is specified as E1.234 + 3.
*1
*1: + 3 represents 10
3
in E1.234 + 3.
Figure 9.96 Real number specification
Table9.12 When an overflow or underflow has occurred
Overflow
Underflow
OPERATION ERROR (error code: 4141)
Turned to 0 without any error
X1
E1.234
D0
EMOVP
Example
Example