172 • SMP Gateway User Manual
17.1.4.4 Mathematical Functions
You can use the following built-in mathematical functions in expressions:
Function Description
Abs( x ) Calculates the absolute value of x.
Pow( x, y ) Calculates the value of x to the power of y.
Sqrt( x ) Calculates the square root of x.
Exp( x ) Calculates the value of e raised to the power of x.
Log( x ) Calculates the logarithm of x to the base 10.
Sin( x ) Calculates the sine of angle x, expressed in radians.
Cos( x ) Calculates the cosine of angle x, expressed in radians.
Tan( x ) Calculates the tangent of angle x, expressed in radians.
ArcSin( x ) Calculates the arcsine of angle x.
ArcCos( x ) Calculates the arccosine of angle x.
ArcTan( x ) Calculates the arctangent of angle x.
Min( x, y ) Compares the values of x and y, and retains the lesser of the two.
Max( x, y ) Compares the values of x and y, and retains the greater of the
two.
17.1.4.5 Data Point Functions
You can use the following built-in data point functions in expressions.
Function Description
Imbalance( point A, point B, point C
)
Calculates the imbalance among three phases, for the current
represented by the three data point names.
The calculation is defined as follows for a three-phase current:
((Imax - Imin) / Iavg) * 100
where:
Iavg = (AI + AB + IC) / 3
Imax = max (IA, IB, IC)
Imin = min (IA, IB, IC)
IsEqual( point1, point2, precision ) Compares point1 and point2, to the nearest precision significant
digits.
The expression evaluates to TRUE or FALSE, depending on
whether or not point1 = point2.
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