FB_BA_Hys_21

The template represents two hysteresis functions with fixed switching points.

It is used to monitor analog values, such as an air filter.

The hysteresis function HysPreAlarm triggers a pre-alarm. Maintenance can take place on an air filter, for example.

The hysteresis function HysMainAlarm triggers a main alarm and can be used as a fault that results in plant shutdown. The air filter must be serviced.

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

Block diagram

Syntax

FUNCTION_BLOCK FB_BA_Hys_21 EXTENDS FB_BA_View
VAR_INPUT
  bEn                : BOOL;
  fIn                : REAL;
END_VAR
VAR_OUTPUT
  bDst               : BOOL;
END_VAR
VAR_INPUT CONSTANT
  HysPreAlarmOn      : FB_BA_AV_Op;
  HysPreAlarmOff     : FB_BA_AV_Op;
  HysMainAlarmOn     : FB_BA_AV_Op;
  HysMainAlarmOff    : FB_BA_AV_Op;
  DstPreAlarm        : FB_BA_BV;
  DstMainAlarm       : FB_BA_BV;
END_VAR
VAR
  HysPreAlarm        : FB_BA_Swi2P;
  HysMainAlarm       : FB_BA_Swi2P;
END_VAR

Inputs

Name	Type	Description
bEn	BOOL	General enable of the function block.
fIn	REAL	Actual value

Outputs

Name	Type	Description
bDst	BOOL	Display of a fault or the BV object is active. bDst is only active if the property bEventDetectionEnable of the BV object was set to TRUE. The monitoring of the binary feedback indicates a fault.

Name

Type

Description

bDst

BOOL

Display of a fault or the BV object is active.

bDst is only active if the property bEventDetectionEnable of the BV object was set to TRUE.

The monitoring of the binary feedback indicates a fault.

Inputs CONSTANT

Name	Type	Description
HysPreAlarmOn	FB_BA_AV_Op	AV object for entering the upper limit value of the hysteresis function HysPreAlarm.
HysPreAlarmOff	FB_BA_AV_Op	AV object for entering the lower limit value of the hysteresis function HysPreAlarm.
HysMainAlarmOn	FB_BA_AV_Op	AV object for entering the upper limit value of the hysteresis function HysMainAlarm.
HysMainAlarmOff	FB_BA_AV_Op	AV object for entering the lower limit value of the hysteresis function HysMainAlarm.
DstPreAlarm	FB_BA_BV	The binary object is used to indicate the pre-alarm of the hysteresis function HysPreAlarm. A message is triggered via Intrinsic Reporting.
DstMainAlarm	FB_BA_BV	The binary object is used to indicate the main alarm of the hysteresis function HysMainAlarm. A message is triggered via Intrinsic Reporting. A fault that results in plant shutdown must be parameterized in the FB_init method via eEnPlantLock.

Variables

Name	Type	Description
HysPreAlarm	FB_BA_Swi2P	The function block is the core of the hysteresis function pre-alarm.
HysMainAlarm	FB_BA_Swi2P	The function block is the core of the hysteresis function main alarm.

Requirements

Development environment	Necessary function
TwinCAT from v3.1.4024.35	TF8040 \| TwinCAT Building Automation from V5.2.1.0