Documentation

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

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.

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

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

Application example

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.