What is KNX?
Ross Bousie of the Royal Melbourne Institute of Technology details the global standard for building and home automation control.
In order to transfer control data to all building management components, a system is required that does away with the problems of isolated devices by ensuring that all components communicate via one common language.
KNX is the world’s only open standard for home and building control and is compliant to EN 50090, EN 13321-1 and ISO/ IEC 14543, and has been submitted for Australian standards approval.
Unlike proprietary protocols, which only the manufacturer supports, KNX is an open worldwide standard with over 300 manufacturers producing products that all interoperate together for a seamless solution. KNX is the perfect choice for a complete integrated project and provides not just lighting control but a total solution for your building control system.
A global standard
KNX future proofs your decision and investment:
● Product Certification guarantees interoperability and interworking of products.
● KNX Association requires a high level of production and quality control during all stages of the product life.
● It’s a unique manufacturer independent Engineering Tool Software (ETS). This tool allows all components to be managed in one software tool.
● KNX can be used for all applications in home and building control.
● There is one protocol no matter what the solution or building type.
● It provides support of different communication media that interoperate to suit the project:
- TP – Twisted pair
- PL – Power line
- RF – Radio Frequency
- IP – Ethernet
● KNX can be coupled to other systems old or new where required, and
● KNX is independent from any hardware or software technology.
You can choose the best product that suits your project and provides design flexibility in function and finishes. The RF switches are very good for refits of Heritage-listed buildings due to no wiring requirements.
There is real ongoing product development by over 300 companies.
Why KNX is needed
These days it is a must to keep energy costs down in a building and this is getting harder to do with different systems such as lighting, HVAC (heating, ventilation and air-conditioning) and access control all having their own control systems. Integrating them to work together is becoming harder and harder as the systems get more complex. Imagine trying to integrate your current lighting systems to work with shutters and HVAC systems and then manage time themes for their use. This would be very hard to do with separate systems and different application tools. Yes it can be done, but it is very difficult and the expertise and labour required to do it would probably make it not cost-effective.
KNX allows for different manufacturers’ equipment to be sourced for the best fit-for-purpose. It then allows for the integration of all the equipment to talk to each other over a standard protocol. This also allows for very tight control over the building functions.
As the KNX protocol can be put over an IP network it also allows:
● for remote control to a central building control centre in order to manage many buildings from one point
● energy data to be collected and analysed for fine-tuning of performance, and
● building managers to be mobile using the internet and ETS software or display software to manage their buildings.
If you are looking at a new building, a refit or just implementing KNX in specific areas or functions of a building, it makes sense to look at an open protocol over a system that functions as a standalone. KNX is scalable from a small domestic installation to the management of an entire city – all using the same tools and protocol. The wiring system KNX employs makes it easy to add additional equipment to your building. If you want, for example, another energy monitor, you can just add it in and pick up the bus from a nearby device.
The advantages KNX offers in having fine control of all the building functions allows substantial energy savings. Documented tests for energy saving using KNX have proven that it has a very short payback on investment.
Support for KNX products is also excellent as the manufacturers must provide good documentation as part of their approval process and are required to have their products independently tested. Support forums are building rapidly and KNX associations have formed in most countries.
Installation of KNX is generally undertaken by electrical contractors doing the cabling and installing the sensor, switches and actuators, etc. Then a systems integrator installs the programs and commissions the installation. A handover to the building manager is then done.
The systems integrator may later work with the building manager to fine-tune the systems, or the building manager can do their own adjustments and tuning. Depending on the project and the expertise required, there is usually a relationship built up between the building manager, the system integrator and the manufacturers.
There is an accredited structured training system administered from the KNX head office in Brussels, made up of two courses: basic and advanced. In Australia, RMIT University is an accredited training organisation and runs courses on a regular basis.
The accredited courses are registered with KNX and recognised around the world. RMIT University has set up a partnership with leading power and automation engineering company ABB Australia, which supplied RMIT with training rigs and supported the staff in training.
The equipment is getting plenty of use as the students in the diploma of electrical engineering are doing a project as part of the course.
The students have been creating new products for KNX, such as an exit light tester that tests the light, battery and other parameters, and creates a report that can be accessed via the ETS software. The electrical apprentices have also been using the equipment in their training.
The basic accredited courses cover the following: augments, communications, topology, telegrams, bus devices, power line installation, planning, commissioning, and diagnostics.
Customised training courses can be devised by RMIT University to suit customer requirements. It offers wiring courses for electrical contractors, seminar training for consultants and specific training for particular equipment.