FB_BA_SlidingLimit

The template represents a sliding limit value monitoring.

After the start, a check is made whether the actual value fSensor of the control is within the tolerance range between the lower limit value fLowLimit and the upper limit value fHighLimit of the function block SlidingLimit. If the actual value is outside this tolerance range and the delay time TiDly has expired, one of the variables bHighLimit or bLowLimit is set depending on whether the tolerance range has been left.

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

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_SlidingLimit EXTENDS FB_BA_View
VAR_INPUT
  bEn             : BOOL;
  fActuator       : REAL;
  fSensor         : REAL;
END_VAR
VAR_OUTPUT
  bHighLimit      : BOOL;
  bLowLimit       : BOOL;
END_VAR
VAR_INPUT CONSTANT
  Hys             : FB_BA_AV_Op;
  TiDly           : FB_BA_AV_Op;
  HighLimitOn     : FB_BA_BV;
  LowLimitOn      : FB_BA_BV;
END_VAR
VAR
  SlidingLimit    : FB_BA_SlidingLimitCtrl;
END_VAR

Inputs

Name	Type	Description
bEn	BOOL	General enable of the template.
fActuator	REAL	The base value of the tolerance range is connected to the input. This value can be, for example, a valve position.
fSensor	REAL	The analog value to be monitored is connected to the input. This value could, for example, be the feedback signal of a valve.

Name

Type

Description

bEn

BOOL

General enable of the template.

fActuator

REAL

The base value of the tolerance range is connected to the input.

This value can be, for example, a valve position.

fSensor

REAL

The analog value to be monitored is connected to the input.

This value could, for example, be the feedback signal of a valve.

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
Hys	FB_BA_AV_Op	Analog value object for entering the hysteresis of the tolerance range. Lower limit of the function block SlidingLimit: fLowLimit = fActuator - (Hys / 2) Upper limit of the function block SlidingLimit: fHighLimit = fActuator + (Hys / 2)
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
SlidingLimit	FB_BA_SlidingLimitCtrl	Core of the template.

Requirements

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