Existing technologies in building automation
The building automation industry is vast and comprises thousands of manufacturers around the world. There are thousands and thousands of devices, equipment and components needed to automate the functions of a building. However, for efficient building automation, a central system is required that can integrate all devices, of different types and brands, safely and efficiently.
In addition to standards, a number of technologies have made building automation possible at the level we know today. Let’s look at some of the main ones.
BACnet
BACnet is a communication protocol for Building Automation and Control (BAC) networks that uses the ASHRAE, ANSI protocol and the ISO 16484-5 standard.
BACnet is designed to enable communication of building automation and control systems for applications such as heating, ventilation and air conditioning (HVAC) control, lighting control, access control and fire detection systems and their associated equipment. The BACnet protocol provides mechanisms for computerized building automation devices to exchange information, regardless of the specific building service they perform.
Development of the BACnet protocol began in June 1987, in Nashville, Tennessee, at the inaugural meeting of the ASHRAE BACnet committee, known at the time as SPC 135P, “EMCS Message Protocol”. The committee worked to reach consensus using working groups to share the task of creating a standard. The working groups focused on specific areas and provided information and recommendations to the main committee. The first three working groups were the Data Types and Attributes Working Group, the Primitive Data Format Working Group, and the Application Services Working Group.
BACnet became ASHRAE/ANSI 135 standard in 1995, and ISO 16484-5 in 2003. The BACnet Compliance Test Method was published in 2003 as BSR/ASHRAE Standard 135.1. BACnet is under ongoing maintenance by ASHRAE Standing Standard Project Committee 135.
BACnet had an almost immediate impact on the HVAC controls industry. In 1996, Alerton announced a complete line of BACnet products for HVAC controls, from the operator’s workstation to small variable air volume (VAV) controllers. Automated Logic Corporation and Delta Controls soon followed suit. On July 12, 2017, BACnet reached a milestone with the issuance of the 1000th Vendor ID. Vendor IDs are assigned by ASHRAE and distributed internationally. These vendor identifiers can be viewed on the BACnet website.
DALI
Digital Addressable Lighting Interface (DALI) is a registered trademark for network-based products that control lighting. This technology was established by a consortium of lighting equipment manufacturers as a successor to 1-10V/0-10V lighting control systems and as an open standard alternative to various proprietary protocols. The trademarks DALI, DALI-2 and D4i are owned by the lighting industry alliance, DiiA (Digital Illumination Interface Alliance).
DALI is specified by a series of technical standards in IEC 62386. Compliance with the standards ensures that equipment from different manufacturers interoperates. The DALI mark is permitted on devices that meet DiiA testing and certification requirements and are listed as registered (DALI version-1) or certified (DALI-2) on the DiiA website. D4i certification – an extension of DALI-2 – was added by DiiA in November 2019.
KNX
KNX is an open standard (EN 50090, ISO/IEC 14543) for automation of commercial and domestic buildings. KNX devices can manage lighting, blinds and drapes, HVAC, security systems, power management, audio and video, white goods (appliances), screens and displays, TV remote control and electronic devices, etc. KNX evolved from three earlier standards: the European Home Systems Protocol (EHS), BatiBUS and the European Installation Bus (EIB or Instabus).
KNX can be implemented via twisted pair (in tree, line or star topology), powerline, RF or IP links. In this model, devices form a network of distributed applications and efficient integration is possible. This is implemented through interworking models with standardized data point types and objects, modeling logical device channels.