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.

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 to the right

• 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:

• MATH - Calculate Expression

Rung Example: