Omron CP - PROGRAMMING MANUAL 05-2007 - Page 596

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Double-precision Floating-point Instructions Section 3-15
Description PWRD(860) raises the double-precision (64-bit) floating-point number in
words B to B+3 to the power of the double-precision (64-bit) floating-point
number in words E to E+3. In other words, PWR(840) calculates X
Y
(X = con-
tent of B to B+3; Y = content of E to E+3).
For example, when the base words (B to B+3) contain 3.1 and the exponent
words (E to E+3) contain 3, the result is 3.1
3
or 29.791.
If the absolute value of the result is greater than the maximum value that can
be expressed as floating-point data, the Overflow Flag will turn ON.
If the absolute value of the result is less than the minimum value that can be
expressed as floating-point data, the Underflow Flag will turn ON.
Flags
Precautions The base data (B to B+3) and the exponent data (E to E+3) must be in
IEEE754 floating-point data format.
3-15-21 Double-precision Floating-point Input Instructions
Purpose These input comparison instructions compare two double-precision floating
point values (64-bit IEEE754 format) and create an ON execution condition
when the comparison condition is true.
Ladder Symbol
→
S1+1 S1S1+3 S1+2 D+1 DD+3 D+2
S2+1 S2S2+3 S2+2
Exponent data
Base data
Name Label Operation
Error Flag ER ON if the base data (B to B+3) or exponent data (E to
E+3) is not recognized as floating-point data.
ON if the base data (B to B+3) or exponent data (E to
E+3) is not a number (NaN).
ON if the base data (B to B+3) is 0 and the exponent data
(E to E+3) is less than 0. (Division by 0)
ON if the base data (B to B+3) is negative and the expo-
nent data (E to E+3) is non-integer. (Root of a negative
number)
OFF in all other cases.
Equals Flag = ON if both the exponent and mantissa of the result are 0.
OFF in all other cases.
Overflow Flag OF ON if the absolute value of the result is too large to be
expressed as a double-precision floating-point value.
Underflow Flag UF ON if the absolute value of the result is too small to be
expressed as a double-precision floating-point value.
Negative Flag N ON if the result is negative.
OFF in all other cases.
S
1
S
2
S 1 : Comparison data 1
S
2 : Comparison data 2
Symbol & options