BAC_PID_01

Functional description

The template BAC_PID_01 is a universal PID controller.
The set value, actual value and control output are referenced via the BACnet value objects X, W and Y.
The PID controller is enabled via the input variable bEn.

Interface

BAC_PID_01 1:

Block diagram

VAR_INPUT

bEn   : BOOL; 
rX    : REAL;
rW    : REAL; 
rSync : REAL;
bSync : BOOL;

bEn: Enable

rX: Actual value

rW: Set value

rSync: Synchronisation value

bSync: Start synchronisation

VAR_OUTPUT

rY        : REAL;
rYMax     : REAL;
rYMin     : REAL;

rY: Control value output

rYMax: Maximum controller value

rYMin: Minimum controller value

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
X	FB_BACnetAVDisplay	The AV object is referenced to the actual value input of the BACnet loop object
W	FB_BACnetAVDisplay	The AV object displays the setpoint of the input rW and is referenced to the setpoint input of the BACnet loop object
En	FB_BACnetBV1204	The BV object is used to display the controller enable in the MCL or in a local operator display
PID	FB_BACnetLoop1201	PID controller
rtrigSync	R_TRIG	A rising edge at input bSync triggers synchronization of the loop object to the value of rSync.
Y	FB_BACnetAVSetpoint	The AV object is referenced to the control value output of the BACnet loop object

Version history

Version number	Comments
1.0.1	First release