Topic: DMD0087
ACOS - Arccosine in Radians
This instruction can only be used in the Expression parameter of the Calculate Expression (MATH) instruction.
The Arccosine in Radians (ACOS) math function will compute the inverse cosine of the function expression.
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.
The range of acceptable input values is -1.0 to +1.0. A value outside this range will generate an 'Argument Out of Range' warning - $OutOfRange (ST132) will be ON.
The output value will be in radians, in the range of 0 to 3.14159 (0 to π).
Some examples:
ACOS( -1.0 ) = π
ACOS( 0.0 ) = 1.571 (π/2)
ACOS( +1.0 ) = 0.0
If the result needs to be in degrees, use the DEG function on the resulting function, for example, DEG( ACOS( 0.0 ) ) = 90.0 degrees.
See Also:
ACOS - Arccosine in Radians
Related Topics:
DEG - Convert Radians to Degrees
RAD - Convert Degrees to Radians
Rung Example:
