Internet of Things Communication Protocol-BACnet

summarize

IoT development has unique product characteristics and application environments in various fields; therefore various types ofIoT protocolsGradually evolving in their respective industries and becoming specific standards as they become more and more used, BACnet (Building Automation and Control Networks Building Automation and Control Networks) is one of the popular automation and control protocols used in the products of leading industry suppliers such asJohnson Controls Inc.Siemens Building Technologies (Siemens building technologies).KMC Controls, remote control systems, etc. It is a networking standard developed by the American Heating, Refrigeration and Air Conditioning Engineers. The American National Standards Institute (ANSI) and the International Organization Standard (ISO) have also adopted BACnet as the standard for networking building automation systems.

BACnet applications are very wide-ranging; BACnet applications include lighting control, security, fire control, alarms, HVAC (heating, ventilation, air conditioning and interfacing with utility companies).

BACnet International (BACnet International)Responsible for conformance testing services as well as the development and adoption of the BACnet standard.

Development History

In 1987, a round table on "Standardized Energy Management System Protocols" was held in New York, USA, for the first time, consisting of experts in the field of building automation, and it was decided that the ASHRAE (ASHRAE) would be responsible for the development of the standardized energy management system.American Society of Heating, Refrigerating and Air-Conditioning Engineers (American Society of Heating, Refrigerating and Air-Conditioning Engineers)BACnet is a standardized data communication protocol for building automation networks, known as BACnet. After 15 years of discussions and reviews, BACnet was finally recognized by the world at the Round Table Conference in 2003 and became the international standard for buildings - ISO16484-5.

1987.01 - ASHRAE initiated the formation of SPC 135p Committee - Standard Project Committee 135p
1991.08 - First public review of draft standards
1994.03 - Second public review of draft standards
1995.03 - Third public review of draft standards
1995.06 - Formalization as an ASHRAE standard
1995.12 - Approved as an American National Standard and officially named ANSI/ASHRAE Standard 135-1995
2002.01 - Official release of new version of ANSI/ASHRAE 135-2001 standard
2003.01 - Became an official ISO standard ISO16484-5

Protocol Architecture

Type of service

Four service primitives are defined: request, indication, response, and confirm, and the protocol defines the following kinds of services

• There is a confirmed service: marked with CONF_SERV. Existence of client/server model, distinction between "requesting BACnet user" and "responding BACnet user", etc.
• Unconfirmed service: marked with UNCONF_SERV.
• Segment acknowledgement (SEGMENT) service: marked with SEGMENT_ACK.
• Error (ERROR) service.
• Reject (REJECT) service.
• Abort (ABORT) services

PDU type

Information in the original language, passed by various protocol data units (PDU: Protocol Data Unit)

• BACnet has confirmed request PDUs
• BACnet Unconfirmed Request PDU
• BACnet Simple Acknowledgement PDU
• BACnet Complex Acknowledgement PDUs
• BACnet Segmentation Acknowledgement PDU
• BACnet error PDUs
• BACnet rejects PDUs
• BACnet Abort PDU

Service Options

• Document access services
• Object Access Service
• Remote device management services
• Who-Has and I-Have services
• Who-Is and I-Am services
• VTS

Object:

The object Obiect is an abstraction of a feature in a real device. Objects in the real world have two common features: they all have state and behavior. For example a dog has its own state (e.g. name, color, birth, and hunger, etc.) and behavior (e.g. wagging tail, etc.). Similarly a bicycle has its own state (e.g., current gear, two wheels, etc.) and behavior (e.g., braking, accelerating, decelerating, and changing gears, etc.).

1. Analog Input Object Type (AIO)
2. Analog Output Object Type (AOT)
3. Analog Value Object Type (AVOT)
4. Binary Input Object Type (BIOT)
5. Binary Output Object Type (BOOT)
6. Binary Value Object Type (BVOT)
7. Calendar Object Type (Date Sheet Object Type)
8. Command Object Type (Command Object Type)
9. Device Object Type (Device Object Type)
10. Event Enrollment Object Type (EOT)
11. File Object Type
12. Group Object Type
13. Loop Object Type
14. Multi-state Input Object Type (Multi-state Input Object Type)
15. Multi-state Output Object Type (Multi-state Output Object Type)
16. Notification Class Object Type (NCOT)
17. Program Object Type (Program Object Type)
18. Schedule Object Type (Schedule Object Type)

BACnet architecture

Typical application areas

• Heating, ventilation and air conditioning
• lighting control
• Elevator monitoring
• access control
• Security and fire alarm system monitoring and integration
• Energy management and energy services
• Operational data

Related resources

• BACnet Committee: Also known as SSPC 135 (Standing Standards Program Committee) of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). It develops and continuously maintains the BACnet standard
• BACnet Test Lab (BTL): It establishes test requirements, issues product certifications, and maintains all BACnet test productGlobal database
• BACnet Institute: A BACnet-centric online portal for learning and knowledge sharing. It includes several BACnet introductory online courses as well as a library of selected articles, presentations, white papers and other BACnet information.
• BACnet International: Promote BACnet implementation adoption through education, promotion and interoperability testing activities.
• BIG-CA: Development and adoption of BACnet for open data exchange and interoperability of building automation components in the China-Asia region

BACnet Related Knowledge Documentation

• BACnet Basics (ODP) (PDF)
• BACnet Developer Workshop (ODP) (PDF)
• BACnet Essential Objects Services (ODP) (PDF)
• BACnet/IP Details (ODP) (PDF)
• BACnet MS/TP Details (ODP) (PDF)
• BACnet Network Configuration (ODP) (PDF)
• BACnet Network Tools (ODP) (PDF)
• BACnet Efficient Networks (ODP) (PDF)
• BACnet Packet Structure Encoding (ODP) (PDF)
• BACnet Testing and Certifying Products (ODP) (PDF)