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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). ( Section 2.4.4)
(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.
(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.
*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 9.95 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 D0EMOVP
Example
Example
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