Topic: DMD0101
FRAC - Fractional Portion of a Real Number
This instruction can only be used in the Expression parameter of the Calculate Expression (MATH) instruction.
The Fractional Portion of a Real Number (FRAC) instruction returns only the fractional portion of a Real number, that is, the portion to the right of the decimal point. Negative real numbers return negative values.
Note: Use the F9 key or click the 'three dot box' at the right edge of the parameter field to open the Default Element Selection Tool (the Element Picker or the Element Browser) or use the Down-Arrow key (Auto-Complete) on any parameter field to see a complete list of the memory locations that are valid for that parameter of the instruction.
Result specifies a location to store the result of the calculation. This can be any writable numeric location.
The Expression parameter consists of all the text between the bounding parentheses. Any expression parameter can be a constant value, a bit or numeric memory location, an arithmetic expression, and/or mathematical function or other expressions up to a maximum of 1024 characters. Expressions can be nested, so use of parentheses is recommended to ensure proper evaluation order.
Since this math function returns a floating point value the Result variable will always be a Real (floating point) type. In the example shown above:
If R1 = 3.14159 the value in R0 would be 0.14159
If R1 = -3.14159 the value in R0 would be -0.14159
If R1 = 3.0 the value in R0 would be 0.0
If R1 = 0 the value in R0 would be 0.0
See Also:
FRAC - Fractional portion of a Real Number
ROUND - Round Real to Nearest Whole Number
TRUNC - Truncate Real to Whole Number
Related Topics:
Rung Example:
