AIN1.EXP

(* @NESTEDCOMMENTS := 'Yes' *)
(* @PATH := '\/Engineering\/signal processing' *)
(* @OBJECTFLAGS := '0, 8' *)
(* @SYMFILEFLAGS := '2048' *)
FUNCTION_BLOCK AIN1
VAR_INPUT
	in : DWORD;
END_VAR
VAR_INPUT CONSTANT
	sign_bit : INT := 255;
	error_bit : INT := 255;
	error_code_en : BOOL;
	error_code : DWORD;
	overflow_bit : INT := 255;
	overflow_code_en : BOOL;
	overflow_code : DWORD;
	Bit_0 : INT;
	Bit_N : INT := 31;
	out_min : REAL;
	out_max : REAL := 10.0;
	code_min : DWORD;
	code_max : DWORD := 16#FFFFFFFF;
	error_output : REAL;
	overflow_output : REAL := 10.0;
END_VAR
VAR_OUTPUT
	out : REAL;
	sign : BOOL;
	error : BOOL;
	overflow : BOOL;
END_VAR
VAR
	tB: DWORD;
END_VAR

(*
version 1.3	10. mar. 2009
programmer 	oscat
tested by		tobias

Ain1 converts signals from A/D converters or other digital sources to an internal real value.

*) 
(* @END_DECLARATION := '0' *)
(* extract error bit *)
error := ((SHR(in,error_bit) AND 16#0000_0001) = 1) OR (error_code_en AND error_code = in);
IF error THEN
	out := error_output;
	RETURN;
END_IF;

(* strip off the data input *)
tb := SHR(SHL(in, 31 - bit_N), 31 - bit_N + Bit_0);

(* extract overflow bit *)
overflow := ((SHR(in,overflow_bit) AND 16#0000_0001) = 1) OR (overflow_code_en AND overflow_code = in) OR (tb < code_min OR tb > code_max);
IF overflow THEN
	out := overflow_output;
	RETURN;
END_IF;

(* extract sign bit *)
sign := (SHR(in,sign_bit) AND 16#0000_0001) = 1;

(* convert in to out *)
out := (DWORD_TO_REAL(tb - code_min) * (out_max - out_min) / DWORD_TO_REAL(code_max - code_min) + out_min);
IF sign THEN out := out * -1.0; END_IF;



(* revision history
hm	23. feb 2008	rev 1.0
	original version

hm	16. mar 2008	rev 1.1
	added type conversions to avoid warnngs under codesys 30

hm	22. apr. 2008	rev 1.2
	corrected error in formula when code_min was set
	corrected error when sign bit was used
	optimized code for better performance

hm	10. mar. 2009	rev 1.3
	real constants updated to new systax using dot

*)
END_FUNCTION_BLOCK