Mitsubishi Electric MELSEC iQ-R Series - Page 824

822
7 APPLICATION INSTRUCTIONS
7.9 Real Number Instructions
Processing details
• These instructions calculate the exponent of the value specified by (s), and store the operation result in the device specified
by (d).
• Exponent operation is performed with the base (e) set to "2.71828".
• If the operation result is -0 or an underflow occurs, the operation result turns out to 0.
• When an input value is set using the engineering tool, a rounding error may occur. Refer to the following for the precautions
on setting input values using the engineering tool.
Page 49 Precautions
Operation error
• The EXPD(P) instruction performs operation using the natural logarithm. To determine a value using the
common logarithm, determine a value by dividing the common logarithm value by 0.43429 and specify it in
the device specified by (s).
Error code
(SD0)
Description
3402H The value input to (s) is -0, a subnormal number, NaN (not a number), or .
3403H The data output from (d) exceeds the following range. (An overflow has occurred.)
|(d)|<2
1024
( ) ( )
(s)(s)+3 (s)+1(s)+2
(d)(d)+3 (d)+1(d)+2
Double-precision real number Double-precision real number
10
X
= e
0.43429
X