Description The STEP 7 Micro/WIN standard library does include the trigonometric functions sine, cosine and tangent in floating point arithmetic. However, their inverse functions, the socalled arc functions, are not available in the standard library.
The arc functions  arc sine, arc cosine, arc tangent  are available for downloading at the end of this entry in the form of a STEP 7 Micro/WIN library.
Description of the "Arc functions" library
Fig. 1: Arc functions library in STEP 7 Micro/WIN
The arc sine function (ARCSIN)
The arc sine function is the inverse function of the sine function:
y = arcssin (x) = sin^{1}(x)
Fig. 2: ARCSIN
Parameter 
Data type 
Function 
Input 
[REAL] 
Function value x: Angle specification in radian measure 
Output 
[REAL] 
Function value y: Angle output in radian measure 
Table 1: Parameters of ARCSIN
Converting from radians to degrees
Angle_{[radian]} = (Angle_{[degree]} * PI) / 180
The arc cosine function (ARCCOS)
The arc cosine function is the inverse function of the cosine function:
y = arccos (x) = cos^{1}(x)
Fig. 3: ARCCOS
Parameter 
Data type 
Function 
Input 
[REAL] 
Function value x: Angle specification in radian measure 
Output 
[REAL] 
Function value y: Angle output in radian measure 
Table 2: Parameters of ARCCOS
Converting from degrees to radians
Angle_{[radian]} = (Angle_{[degree]} * PI) / 180
The arc tangent function (ARCTAN)
The arc tangent function is the inverse function of the tangent function:
y = arctan (x) = tan^{1}(x)
Fig. 4: ARCTAN
Parameter 
Data type 
Function 
Input 
[REAL] 
Function value x: Angle specification in radian measure 
Output 
[REAL] 
Function value y: Angle output in radian measure 
Table 3: Parameters of ARCTAN
Converting from radians to degrees
Angle_{[radian]} = (Angle_{[degree]} * PI) / 180
The STEP 7 Micro/WIN library as archive file Copy the "arcusfunctions.exe" file into a separate directory and then start the file with a doubleclick. The STEP 7 Micro/WIN library is then unpacked. You can then integrate the library, which can be used in version V3.2.4.27 and higher of STEP 7 Micro/WIN, into your S7200 project.
Notes
 Information about inserting libraries in STEP 7 Micro/WIN is available in
Entry ID: 16689345
arcusfunctions.exe ( 36 KB )
Addition Keywords Arc tangent, Arc cosine, Arc sine, Arc function
