====== Two-point function ======

{{:en:mervis-ide:35-help:b80.png}}

===== Block name =====

B80_TWOPOINTFUNCTION

===== ST call =====

<code st-iec>
Version V1.0
PROGRAM TEST B80
   VAR
 REAL1,REAL2: REAL;    
  END_VAR
 REAL2 := LIB.CORE.V1_0.B80_TWOPOINTFUNCTION(IN:=REAL1, X1:=20,X2:=20,Y1:=0,Y2:=100);
END_PROGRAM

Version V1.1
PROGRAM TEST2_B80
    VAR
     FB:LIB.CORE.V1_1.B80_TWOPOINTFUNCTION;
      IN_V:REAL;
      X1_V:REAL:=20;
      X2_V:REAL:=20;
      Y1_V:REAL:=0;
       Y2_V:REAL:=100;
     OUT_V:REAL;
 END_VAR 
FB(IN:=IN_V, X1:=X1_V, X2:=X2_V, Y1:=Y1_V, Y2:=Y2_V);
OUT_V:=FB.OUT;
END_PROGRAM
</code>

===== Library =====

LIB\CORE

===== Version =====

V1.1

===== Description =====

Linear function, recalculation of input value to output value defined by two points.\\


===== Inputs =====

|Input|Type|Description          |Default value|
|IN   |REAL|Input signal         |0            |
|X1   |REAL|1.point, x coordinate|20           |
|X2   |REAL|2.point, x coordinate|50           |
|Y1   |REAL|1.point, y coordinate|0            |
|Y2   |REAL|2.point, y coordinate|100          |

===== Outputs =====

|Output|Type|Description              |
|OUT   |REAL|Output signal            |
|SIGN  |BOOL|Sign of the output signal|

===== Function =====

The block implements a transfer function given by two points, //[X1,Y1]// and //[X2,Y2]//, see figure below. The points do not have fixed order, both //X1<X2// and //X1>X2// is possible. If //X1=X2// then //y=Y1// for //x<X1//, //y=Y2// otherwise, see figure 2 below. The //sign// output is indicating the sign of the output signal //y//: When //y>= 0// //sign=true//, otherwise //sign=false//.

{{:en:mervis-ide:35-help:b80_1.png}}

Function may be rising or falling, //[X1,Y1]//, //[X2,Y2]//.

{{:en:mervis-ide:35-help:b80_2.png}}

In case that //X1=X2//: value at //x=X1=X2// is given by //Y2//.

===== Application example =====

{{:en:mervis-ide:35-help:b80_example.png}}

Function with internal parameters x1=20, x2=20, y1=0, y2=100.

\\
\\


===== Older version  =====

\\
Version  V1.0 was defined as a function. V1.1 is defined as a function block, therefore it can bes added to graphs and it can be set tu manual mode. Functionality remains without change.