Rockwell Automation GMLC Reference Manual - Manual (Page 680)

Publication GMLC-5.2 - November 1999
643
The argument may be any floating point value or expression. The value of
the Arc_tangent function is always an angle from -
π
/
2
to
π
/
2
radians
(±90°), inclusive.
For example, the following expression is evaluated as 0.7853xx since the
principal angle whose tangent is 1 is 0.7853 radians (45°).
Arc_tangent(1)
To convert the value of the Arc_tangent function to degrees, multiply by
180 /
π
. For example, the following expression is evaluated as 45 (assuming
the user constant Pi has been defined as the value of
π
) since the
principal angle whose tangent is 1 is 45°.
Arc_tangent(1) * 180 / Pi)
Cosine
The value of the Cosine function is the cosine of the argument angle (in
radians), as shown below.
Argument –
+
–
+
−π
/2
+π
/2