Overview of the KNX Standard

The KNX Handbook covers all technical topics of the KNX standard, from the first contact with the KNX technology, through the specification, certification rules and testing, and application descriptions. The different Volumes and Parts are clearly separated, and intended for the various responsibilities within a company.

Volume 1 "Primer"

..shall give a general overview of the whole KNX system and philosophy, and will be useful to all people like product managers, developers, quality assurance people, ... wanting to have a basic knowledge of the KNX system.
This volume is still under preparation, for the time being we refer therefore to Chapter 3/1/1 “Architecture”.

Volume 2 "Guide for Development"

..will contain the basis for the knowledge needed for development of products based on the KNX technology. It will lead technical people to a sufficiently detailed know-how of this technology in order to develop products in this environment.
This Volume is also under preparation, it will be built on the contributions of the main system providers within the KNX Association.

Volume 3 "System Specifications"

.. is the main part of the KNX specification. It shall be used as a reference for hardware and software development of products. As such you need only to refer to the corresponding parts relevant for your development.

• Part 3/1 "Architecture" outlines and interconnects the communication stack, the application environment and management features described in the next parts. It shows the various possibilities offered by the KNX specification.
• Part 3/2 "Communication Media" specifies referring to the OSI-model the Physical Layer and Link Layer for each communication medium for which the KNX-system has been implemented.
• Part 3/3 "Communication" bases on the OSI model for communication to give the requirements for the implementation of a KNX compliant communication stack (common kernel) from Network Layer upwards.
• Part 3/4 "Application Environment" defines the KNX specific environment on top of the communication stack for application development.
• Part 3/5 "Management" draws the specifications for management server features in the devices and management client features within the different configuration modes.
• Part 3/6 "Standardized Interfaces" gives the standardized environment in which application programs may reside: the routines provided by Application Programmer's Interface and the hard- and software features of the Physical External Interface.
• Part 3/7 "Interworking" defines the rules to be followed to build devices and applications able to interwork with other manufacturer’s products within the world of KNX certified products.
• Part 3/8 “KNX KNXNet/IP” will define the use of the KNX protocol on top of the IP protocol. This feature is particularly useful to link and/or extend the KNX network with this now worldwide used communication means. This specification covers all the functionalities for communication, management and remote actions, making KNX networks accessible from “anywhere in the world”.
• Supplements
  Supplements are part of Volume 3 “System Specifications”. They are the result of dedicated workgroups within the KNX Association and define specific aspects of the specification, needed to define the whole spectrum of the KNX system. In order to speed up the availability of the KNX specification, they have been added in Volume 3 in the status where they were approved. They will be integrated in the relevant sections in a further version. The KNX browser gives indication on which chapters the supplements will be allocated to.

Volume 4 "Hardware Specifications and Tests"

..provides you with the constructional requirements for KNX devices, dealing mainly with Electrical, Functional, Environmental Conditions and Quality features needed to comply with the KNX certified design quality level.

• Part 4/1 "Safety and Environmental Requirements for Application Products" lays down hardware requirements to be met for KNX certification by application products. The requirements are based on European standardisation and fix the obligatory use for hardware certification of the European family standard for Home and Building Electronic Systems EN 50090-2-2 in conjunction with an appropriate product standard.
• Part 4/2 "Safety and Environmental Requirements for Basic and System Components" lays down hardware requirements to be met for KNX certification by basic and system components and devices. As for such devices an appropriate product standard is not available, explicit requirements as regards EMC and environmental conditions are given in this handbook part, which have to be complied with for KNX certification. These requirements are in some cases higher than the European family standard for Home and Building Electronic Systems EN 50090-2-2.
• Part 4/3 "Safety and Environmental Requirements EMC Test Setup" is intended as a further elucidation of the EN 50090-2-2 and a support for manufacturers while testing compliance of bus products to the EMC requirements of part 2 and 3'.
• Part 4/4 "Specific Requirements for Application Products and Basic and System Components and Devices" lists additional requirements and/or recommendations for application products as well as basic and system components, other than those specified in Part 1 or 2. The requirements relate to such aspects as quality management system, useful life, power consumption, reliability/failure rates and material recycling.
• Part 4/5 "Installation Safety Requirements" lays down requirements, which have to be taken into account when installing a (Twisted Pair) bus system.
• Part 4/6 "Assessment and Test of Electrical Safety" is intended to support the manufacturer while assessing the compliance of developed bus products to electrical safety requirements. This handbook part amongst others provides a test report form for electrical safety and guidelines for execution of the high voltage tests.

Volume 5 "Certification"

..defines the necessary requirements, steps, and procedures to obtain from the KNX Association the granting of the KNX Trademark for products or services. It will be particularly useful for people in charge for obtaining the KNX Trademark.

Volume 6 "Profiles"

Each profile defines a set of minimum requirements for each of the system specifications categories, enabling development and certification of KNX certifiable devices and systems. Profiles are certification relevant, as only devices or systems compliant to at least one profile may be KNX certified.

Volume 7 "Application Descriptions"

This Volume describes the functional blocks (FB) specifications for the use in the various application fields. Part 7/1 "Common Functional Blocks" specifies FB of common use, mandatory for certification, if used in an application. They have been submitted for approval as KNX standard specification. Functional blocks specified in the next Chapters are declaration relevant only, and shall be considered as experimental standards. Decision upon their definitive approval will be taken after some experience in products. _ 2001, KNX Association v1.1 - page 7 of 8.

Volume 8 "System Conformance Tests"

• Part 8/1 "Introduction" This chapter gives the overall guidelines for testing.
• Part 8/2 "Medium Dependent Layers Tests" contains test specifications for the media on which the KNX protocol has been implemented. These test specifications are especially related to the various physical layer implementations and their respective Link Layer Medium Access Units.
• Part 8/3 "Medium Independent Layer Tests" contains test specifications for the KNX protocol stack layers, this is, for those independent of a physical layer implementation. These test specifications especially relate to the KNX Link Layer, Transport Layer, Network Layer and Application Layer.
• Part 8/4 Empty
• Part 8/5 "Network Management Tests" will be available in a future publication of this KNX Handbook.
• Part 8/6 "Application Interfaces Tests" contains test specifications for the Standardized Interfaces.
• Part 8/7 Interworking Tests contains test specifications for the defined KNX Interworking Standards. Test suite supplements cover testing of specifications laid down in the supplements.

Volume 9 "Standardized Components and Devices and Tests"

• Part 9/1 "Cables and Connectors" describes the requirements and tests for certification of standardised and non-standardised KNX cables and connectors.
• Part 9/2 "Basic Components" contains the requirements and tests for certification of standardised and non-standardised KNX basic components.
• Part 9/3 "Couplers" includes requirements and tests for certification of standardised KNX interfaces and couplers.
• Part 9/4 "BCUs and BIMs" contains the requirements and tests for all currently available and standardised Bus Coupling units and Bus Interface Modules (in their various mechanical constructions).

Volume 10: Application Domain specific Standards

This volume describes the specifications for use in specific application fields. This is mainly the HVAC Easy Extension (HEE) part, designed especially for complex application fields like HVAC.

If you are interested in acquiring a copy of the KNX specifications, please have a look on the pages on KNX membership