Description
You can use the "Form arccosine value" instruction to calculate the size of the angle from the cosine value specified at input IN, which corresponds to this value. Only valid floating-point numbers within the range -1 to +1 can be specified at input IN. The calculated angle size is output in radians at output OUT and can range in value from 0 to +π.
The enable output ENO has the signal state "0" if one of the following conditions applies:
-
Enable input EN has the signal state "0".
-
The value at input IN is not a valid floating-point number.
-
The value at input IN is outside the permitted range (-1 to +1).
Parameters
The following table shows the parameters of the instruction "Form arccosine value":
|
Parameters |
Declaration |
Data type |
Memory area |
Description |
|
|---|---|---|---|---|---|
|
S7-1200 |
S7-1500 |
||||
|
EN |
Input |
BOOL |
I, Q, M, D, L or constant |
I, Q, M, D, L, T, C or constant |
Enable input |
|
ENO |
Output |
BOOL |
I, Q, M, D, L |
I, Q, M, D, L |
Enable output |
|
IN |
Input |
Floating-point numbers |
I, Q, M, D, L, P or constant |
I, Q, M, D, L, P or constant |
Cosine value |
|
OUT |
Output |
Floating-point numbers |
I, Q, M, D, L, P |
I, Q, M, D, L, P |
Size of the angle in radians |
You can select the data type of the instruction from the "???" drop-down list of the instruction box.
For additional information on valid data types, refer to "See also".
Example
The following example shows how the instruction works:
The following table shows how the instruction works using concrete operand values:
|
Parameters |
Operand |
Value |
|---|---|---|
|
IN |
Tag_Value |
0 |
|
OUT |
Tag_Result |
+1.570796 (π/2) |
If the "TagIn" operand has signal state "1", the instruction is executed. The instruction calculates the size of the angle corresponding to the cosine value at input "Tag_Value". The result of the instruction is stored at output "Tag_Result". If the instruction is executed without errors, the "TagOut" output is set.