It’s possible to suppress the PCD Alarms on BACnet?

FAQ #101975

Yes, it’s possible to suppress alarm notifications on BACnet by controlling the communication.
This is an official BACnet mechanism and available with BACnet firmware from 1.24.41 (or newer) and since PG5 2.1.420.

To suppress the alarms it’s necessary to modify the BACnet communication mode of the device as described below.

In general, the communication of the BACnet device is controlled. There are 3 options:

  • (0) Standard communication (default).
    All requests will be answered and device will also send COV, Alarm or Event-notifications if necessary
  • (1) No communication.
    The device will not answer to any request and does not send any COV, Alarm or Event-notifications.
  • (2) Reduced communication. The device will answer all requests, but does not send any COV, Alarm or Event-notifications.
    This mode is usually selected if device is under maintenance and alarm notifications should be suppressed.

To control the communication mode as described above, 1 additional register must be defined and set to the corresponding value. A 2nd register can be used to get the current communication status.

In the example below, a “ComState” and “ComDisable”  register has been defined. The “ComDisable” has to be controlled by application, e,g. via a maintenance switch at the cabinet or a software switch.

The “ComStatus” will show the actual communication status and is a read only.

Finally those 2 register have to be mapped within BACnet Configurator into Device object, property “Communication Status” and “Communication Disable”:

Good to know: DDC Suite 2.7 has implemented this mechanism into BACnet Device FBox for easier use.

If this two new items are used with a BACnet FW < 1.24.41 then BACnet does not start


PCD2 / Mxxx

PCD3 / Mxxx

PCD7 / Rxxx

Communication / BACnet

PCD1 / M2xx0

PG5 2.1

Last update: 21.01.2016 13:46

First release: 21.01.2016 13:33

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