FB_BA_FixedLimitExt

The template represents a limit switch with dynamic limit values.

A tolerance range is defined around the value fIn to be monitored.

The tolerance range results from a high limit value HighLimitValue and a low limit value LowLimitValue.

If the value fIn exceeds the upper limit value of the tolerance range, then the output bHighLimit is set.

A response delay of the output bHighLimit can be parameterized with the time variable TiDly.

The binary object HighLimitOn is used to display bHighLimit and can be used as a fault message object by changing the parameterization.

If the value fIn falls below the lower limit value of the tolerance range, then the output bLowLimit is set.

A response delay of the output bLowLimit can be parameterized with the time variable TiDly.

The binary object LowLimitOn is used to display bLowLimit and can be used as a fault message object by changing the parameterization.

	The initialization of the template takes place within the method FB_Init.

Block diagram

Syntax

FUNCTION_BLOCK FB_BA_FixedLimitExt EXTENDS FB_BA_View
VAR_INPUT
  bEn               : BOOL;
  fIn               : REAL;
  fHighVal          : REAL;
  fLowVal           : REAL;
END_VAR
VAR_OUTPUT
  bHighLimit        : BOOL;
  bLowLimit         : BOOL;
END_VAR
VAR_INPUT CONSTANT
  HighLimitValue    : FB_BA_AV_Op;
  LowLimitValue     : FB_BA_AV_Op;
  TiDly             : FB_BA_AV_Op;
  HighLimitOn       : FB_BA_BV;
  LowLimitOn        : FB_BA_BV;
END_VAR
VAR
  FixedLimit        : FB_BA_FixedLimitCtrl;
END_VAR

Inputs

Name	Type	Description
bEn	BOOL	General enable of the template.
fIn	REAL	The analog value to be monitored is connected to the input, e.g. a differential pressure sensor.
fHighVal	REAL	The upper limit value of the tolerance range is connected to the input.
fLowVal	REAL	The lower limit value of the tolerance range is connected to the input.

Outputs

Name	Type	Description
bHighLimit	BOOL	The output indicates that the upper limit value of the tolerance range has been exceeded.
bLowLimit	BOOL	The output indicates that the value has fallen below the lower limit of the tolerance range.

Inputs CONSTANT

Name	Type	Description
HighLimitValue	FB_BA_AV_Op	Analog value object for entering the upper limit value of the tolerance range.
LowLimitValue	FB_BA_AV_Op	Analog value object for entering the lower limit value of the tolerance range.
TiDly	FB_BA_AV_Op	Analog value object for entering the response delay of the outputs bHighLimit and bLowLimit.
HighLimitOn	FB_BA_BV	The binary object is used to display bHighLimit and can be used as a fault message object by changing the parameterization.
LowLimitOn	FB_BA_BV	The binary object is used to display bHighLimit and can be used as a fault message object by changing the parameterization.

Variables

Name	Type	Description
FixedLimit	FB_BA_FixedLimitCtrl	Core of the template.

Requirements

Development environment	Necessary function
TwinCAT from v3.1.4024.35	TF8040 \| TwinCAT Building Automation from V5.0.0.0