FB_WG_Weighing

The function block FB_WG_Weighing is used to determine a measured weight.

The configuration structure is transferred with ST_WG_Weighing.

Syntax

Declaration:

fbWeighing := FB_WG_Weighing(stConfig := ...)

Definition:

FUNCTION_BLOCK FB_WG_Weighing
VAR_INPUT
    stConfig := ST_WG_Weighing; (*The input parameters of this function block represent initialization parameters and must already be assigned in the declaration of the FB instance! (Alternative: Configure() method)*)
END_VAR
VAR_OUTPUT
    bValidMeasurement  : BOOL := FALSE;    // TRUE if ST_WG_Weighing_Validation-conditions are valid (only if nWindowLength is full).
    bNewResult         : BOOL := FALSE;    // TRUE if a new result has been occured (at the end of the Validation measurement).
    tLastResult        : ULINT := 0;       // Timestamp of new occured result.
    fLastWeight        : LREAL := 0.0;     // Last weighing result.
    fLastStd           : LREAL := 0.0;     // Last standard deviation result.
    fWeight            : LREAL := 0.0;     // Moving average of nWindowLength input values.
    fStd                : LREAL := 0.0;    // Moving standard deviation of nWindowLength input values.
    fMin                : LREAL := 0.0;    // Minimum value of moving nWindowLength input values.
    fMax                : LREAL := 0.0;    // Maximum value of moving nWindowLength input values.
    fAutoTareOffset     : LREAL := 0.0;    // Last auto tare offset result.
    bNewAutoTareResult  : BOOL := FALSE;   // TRUE if a new result has been occured (at the end of the AutoTare measurement).
END_VAR
VAR

Inputs

Name	Type	Description
stConfig	ST_WG_Weighing	Function block-specific configuration structure

Outputs

Name	Type	Description
bError	BOOL	TRUE, if an error occurs.
bConfigured	BOOL	TRUE if the configuration was successful.
ipResultMessage	I_TCMessage	Interface that provides properties and methods for message handling
bValidMeasurement	BOOL	TRUE if the ST_WG_Weighing_Validation conditions are met.
bNewResult	BOOL	TRUE, if a new result was calculated.
tLastResult	ULINT	The timestamp of the last calculated result.
fLastWeight	LREAL	The weight (moving average) of the last result.
fLastHour	LREAL	The standard deviation of the last result.
fWeight	LREAL	The current weight (moving average) of the last result.
fStd	LREAL	The current moving standard deviation.
fMin	LREAL	Minimum fWeight weight in the sliding window.
fMax	LREAL	Maximum fWeight weight in the sliding window.
fAutoTareOffset	LREAL	The tare weight of the last result.
bNewAutoTareResult	BOOL	TRUE if a new tare weight has been calculated.

Methods

Name	Definition location	Description
Configure()	Local	Loads a new (or initial) configuration structure.
Call()	Local	Calculates the output signal for a given input signal and configuration of the function block.
Reset()	Local	Resets internal states.

Properties

Name	Type	Access	Definition location	Initial value	Description
bTraceLevelDefault	BOOL	Get, Set	Local	TRUE	TRUE, if eTraceLevel = Warning.
eTraceLevel	TcEventSeverity	Get, Set	Local	Warning	Severity of an event
nTimeStamp	ULINT	Get, Set	Local	0	Timestamp of the oldest input value of the next Call().

Requirements

Development environment	Target platform	PLC libraries to include
TwinCAT v3.1.4024.50	PC or CX (x64, x86)	Tc3_Weighing

Further Information