CALIBRATE.EXP

(* @NESTEDCOMMENTS := 'Yes' *)
(* @PATH := '\/Engineering\/measurements' *)
(* @OBJECTFLAGS := '0, 8' *)
(* @SYMFILEFLAGS := '2048' *)
FUNCTION_BLOCK CALIBRATE
VAR_INPUT
	X : REAL;
	CO : BOOL;
	CS : BOOL;
END_VAR
VAR_INPUT CONSTANT
	Y_Offset : REAL;
	Y_Scale : REAL;
END_VAR
VAR_OUTPUT
	Y : REAL;
END_VAR
VAR RETAIN
	offset : REAL;
	Scale : REAL := 1.0;
END_VAR

(*
	version 1.3	11. mar. 2009
	programmer 	hugo
	tested BY		hans

Calibrate allows for offset and scale calibration of an analog input.
offset is calibrated to a stored reference Y_offset while CO is true.
after the offset is calibrated, scale can be calibrated to a reference value Y_scale while CS is true.
*)
(* @END_DECLARATION := '0' *)
(* check for calibration *)
IF CO THEN
	OFFSET := Y_Offset - X;
ELSIF CS THEN
	SCALE := Y_scale / (X + OFFSET);
END_IF;
(* calculate output *)
Y := (X + OFFSET) * SCALE;


(* revision history
hm 22.2.2007		rev 1.2
	changed VAR RETAIN PERSISTENT to VAR RETAIN for better compatibility
	wago lon contollers do not support persisitent

hm	11. mar. 2009	rev 1.3
	changed real constants to use dot syntax

*)
END_FUNCTION_BLOCK