BAC_AC_Filter_01

Functional description

The template realises filter monitoring within an air conditioning plant via a differential pressure switch. If the differential pressure switch is triggered, filter contamination is logged.
A rising edge at the binary input of the differential pressure switch switches the RS flip-flop to latching. As a result, the filter contamination continues to be displayed, even if the plant shuts down. The RS flip-flop is reset after a plant restart without actuation of the differential pressure switch.

A BV object is used to display the filter contamination in the OWS.

Interface

BAC_AC_Filter_01 1:

System diagram

BAC_AC_Filter_01 2:

Block diagram

BAC_AC_Filter_01 3:

VAR_INPUT

udiPltStp     : UDINT; 

udiPltStp : The input variable is used to supply the template with the plant steps of the air-conditioning plant.BAC_StartPltStpT_01.

VAR_OUTPUT

bDst     : BOOL;

bDst: The output variable indicates that filter monitoring was triggered and issues an error for further processing.

VAR CONSTANT

PLT_NUM    : BYTE := 1;

PLT_NUM: all alarms and events of all plant components within a controller are included in a global alarm and event list. The assignment of events and alarms to a plant is defined by the assignment of a PLT_NUM plant number.
The recording and processing of an alarm from an aggregate or a device takes place within the templates by means of the alarm function block FB_BA_Alarm.
The evaluation of the alarms of a plant, e.g. for the generation of a collective message or for plant shutdown in case of relevant faults, takes place within the template BAC_PltAlm_01 by means of the function block FB_BA_AlarmPlt.
The evaluation of different plant events within the templates of a plant, takes place within the template BAC_PltComnMsg_01 by means of the function block FB_BA_ComnMsg.

Important! The assignment and evaluation of the alarms and events of a plant can only be done correctly if all templates of a plant have the same plant number!

The plant number can be assigned in the Project Builder in the parameter menu for the templates or via a column in the Excel import.

Program description

Instance

Type

Task

DiffPrssSwi

FB_BACnetBI1203

BI object differential pressure monitor for filter monitoring

tonDiffPrss

TON

Response delay of the filter monitoring

tonDiffPrss

RS

Error message memory for filter monitoring

AlmDiffPrss

FB_BA_Alarm

The collective alarm function block logs the filter monitoring fault and forwards it via an internal variable to the plant alarm collector BAC_PltIniAlm_01

.

DiffPrssAlm

FB_BACnetBV1204

BV object for displaying the filter monitoring

IO linking

Variables for linking with the terminals

Parameter

Type

optional

Process image

 

BI_Differential_Pressure_Switch

BOOL

 

Input

Digital input - message - differential pressure switch

Version history

Version number

Comments

1.0.1

First release