BAC_PltAlm_01

Application

The template BAC_PltAlm_01 deals with the following tasks in a plant:

Collecting the alarms of a plant and bundling them into a group alarm or plant shutdown alarm bAlmShutOff
Display to indicate that an alarm is present in a plant.
Plant-related acknowledgement and resetting of the alarms

Interface

BAC_PltAlm_01 1:

Plant diagram

Block diagram

Block diagram of the internal communication structure

Within the templates the alarms are logged with the function block FB_BA_Alarm. The communication between the function block FB_BA_Alarm and the alarm collector FB_BA_AlarmPlt takes place within the library via a data structure.
It is important that the value of the variable byPltId at the sender of the alarm FB_BA_Alarm and the receiver of the alarm FB_BA_AlarmPlt is identical.

VAR_OUTPUT

bAlmShutOff   : BOOL;
bRst          : BOOL;

bAlmShutOff: A plant shutdown alarm is active.

bRst: When an acknowledgement is triggered, this output is active for one cycle. The pulse can be used to acknowledge faults.

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_PltIniAlm_01 by means of the function block FB_BA_AlarmPlt.
The evaluation of various plant events within the templates of a plant is carried out within the template BAC_PltIniComnMsg_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
Rst	FB_BACnetBVSetpoint	BV object for local acknowledgement of a collective plant alarm.
Rst_rtrig	R_TRIG	The function block Rst_rtrig evaluates the rising edge of the local acknowledgement of BV object Rst.
	OR	The OR link consolidates the local acknowledgement of the BACnet object and the global fault message acknowledgement. The global acknowledgement of alarms from all systems of a controller via the variable g_bRst is triggered in the template BAC_GenAlm_01.
AlarmPlt	FB_BA_AlarmPlt	The function block AlarmPlt is the central function block of this template. It collects the alarms of a plant and pools them in a group alarm.
PrioSwi	FB_BA_PrioSwi_B04	If an alarm is not acknowledged, the output bNewAlarm of the function block AlarmPlt becomes TRUE. In this case the priority switch PrioSwi generates a flashing signal and the output bVal is switched through. A new, unacknowledged alarm is pending. (new value message). If an acknowledged alarm is pending, the priority switch switches through TRUE. The output bVal is permanently on.
AlmInd	FB_BACnetBVDisplay	Display of the group alarms of a plant with new value message.

Version history

Version number	Comments
1.0.1	First release