S_EndAttenuation (FB)

Epec Programming and Libraries Manual

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Supported platforms: CODESYS 3.5, CODESYS 3.5 SAFETY, CODESYS 3.5 SP19 SAFETY

S_EndAttenuation (FB)

Description

This function block limits proportional control value when movement is near the end position.

Initialization

Init method is used to initialize the necessary static calculation parameters for the function block instance.

The method shall be called at least once before the actual function block can be called, i.e. at the application initialization phase.

The method checks the validity of input parameters. However, none of the function block outputs are affected by the initialization.

A parameter error is diagnosed if:

Init method is not called before the main FB call OR
i_pEventCode = 0 OR
i_pEventCodePosDirAtt = 0 OR
i_pEventCodeNegDirAtt = 0 OR
S_i_PosDirAttenuationLimit is out of range OR
S_i_NegDirAttenuationLimit is out of range

Initialization parameters

Parameter	Data type	Unit	Range	Description
S_i_PosDirAttenuationLimit	SAFEUINT	%	0-100	Attenuated positive direction maximum control value. Percent from value 10000.
S_i_NegDirAttenuationLimit	SAFEUINT	%	0-100	Attenuated negative direction minimum control value. Percent from value -10000.
i_pEventCode	POINTER TO EventCode	-	≠0	Pointer to application variable which is type EventCode.
i_pEventCodePosDirAtt	POINTER TO EventCode	-	≠0	Pointer to application variable which is type EventCode.
i_pEventCodeNegDirAtt	POINTER TO EventCode	-	≠0	Pointer to application variable which is type EventCode.

Initialization method return value

TRUE: All initialization parameters ok.

FALSE: Error in initialization parameter(s).

Operation

The output value S_o_Control is limited to the given percentage (S_i_PosDirAttenuationLimit) of the positive max control value if the S_i_Control value is higher than limited value and the corresponding end attenuation flag S_i_PosDirAttenuationOn is true. S_o_Control is limited to given percentage (S_i_NegDirAttenuationLimit) of negative min control value if the S_i_Control value is lower than limited value and the corresponding end attenuation flag S_i_NegDirAttenuationOn is true. Otherwise S_o_Control follows the input value S_i_Control.

See figure below where S_i_PosDirAttenuationLimit = 70 and S_i_NegDirAttenuationLimit = 60 and the corresponding end attenuation input is true when end attenuation limit is reached.

Inputs

Input variable name	Data type	Unit	Range	Description
i_Enable	BOOL	-	-	Enable POU operation
S_i_Control	SAFEINT	-	-10000 - (+)10000	Control value
S_i_PosDirAttenuationOn	SAFEBOOL	-	-	Positive direction end attenuation is active
S_i_PosDirAttenuationOn	SAFEBOOL	-	-	Negative direction end attenuation is active

Outputs

Output variable name	Data type	Unit	Range	Description
S_o_Control	SAFEINT	-	-10000 - (+)10000	Attenuated control value
o_Status	Status	-		Status of output value. See Status structure.

Error diagnostic

See Diagnostic Interface library description of error status and event code functionality.

Conditions	S_o_ Control	o_Status. OutputValid	o_Status error status	Event code FunctionID	Event code EventID
i_Enable TRUE AND init parameter error AND i_pEventCode valid	0	FALSE	ParameterError	END_ATTENUATION	PARAMETER_ERROR
i_Enable TRUE AND init parameter error AND i_pEventCode NULL	0	FALSE	ParameterError	-	-
i_Enable TRUE AND init parameters ok AND S_i_Control within range	Attenuated control value	TRUE	-	NO_FUNC	NO_ERROR
i_Enable TRUE AND init parameters ok AND S_i_Control > 10000	0	FALSE	InputHigh	END_ATTENUATION	INPUT_TOO_HIGH
i_Enable TRUE AND parameters ok AND S_i_Control < -10000	0	FALSE	InputLow	END_ATTENUATION	INPUT_TOO_LOW