Description
BACnet
BACnet ( B uilding A utomation and C ontrol Net work) is a network protocol for building automation. It is developed by the American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE), standardized by ASHRAE 135-2020, ANSI, and ISO 16484-5 and continuously updated. This open standard enables building operators to use BACnet compliant devices from different manufacturers interoperably.
BACnet basics
BACnet defines an object model in which a physical device is represented by a group of standardized BACnet objects. Each object type provides a well defined list of properties. BACnet devices provide various services and procedures to other devices, depending on the complexity of the device. So-called BIBBs (BACnet Interoperability Building Blocks) define the set of services and procedures which must be supported on the server and client side in order to realize certain requirements of the system. BACnet devices are classified by a device profile. Device profiles can range from a simple smart sensor (B-SS) to a complex building controller (B-BC). The PICS (Protocol Implementation Conformance Statement) document associated with a BACnet device lists all supported BIBBs, object types, character sets, and communication options. BACnet devices communicate over network, in most cases via BACnet/IP and to a lesser extent via BACnet MS/TP (BACnet Manager-Subordinate Token-Passing).
CODESYS BACnet
CODESYS BACnet SL enables the implementation of building automation applications in compliance with ANSI/ASHRAE Standard 135-2020. All object types defined in ANSI/ASHRAE Standard 135-2020 and all services required for application development are supported. Integrated libraries, devices and plug-ins enable the configuration and implementation of an application with BACnet support. For example, to provide an analog value (BACnet Analog Value) in the BACnet network, a corresponding BACnet Analog Value device simply has to be inserted in the device tree of the CODESYS application.
Picture 1: Example of a simple BACnet application in CODESYS
