You will often hear terms like ‘guaranteed compatibility’ and a promise of futureproofing used by KNX community. That is because it is probably the only system that offers real assurances that an installation that can be upgraded over time, without going back to the drawing board or commissioning messy installation work. Once an integrator ‘discovers’ KNX, they never look back. We asked Ben Lewis of KNK Consultants for his view on futureproofing
Smart technology cannot stand still: it needs to evolve throughout a building's lifetime if it is to continue adding value. Commercial tenants may want to set up for a completely new way of working or type of business. New sustainability and energy efficiency targets may be imposed, to manage costs and/or to manifest corporate social responsibility. Home owners will get older and their requirements for assisted living will change over time; or maybe new babies come along or older ones come home and they have to find new ways to live alongside adult boomerang kids? Meanwhile, new technologies will come on stream and building users’ aspirations will change.
It’s relatively easy to write timescales and deliverables into a project; but less so to provide for “what if?” scenarios 10 or 20 years down the line? How do we make sure that evolution of their building’s intelligence is even possible, let alone practical and affordable? What should we understand by futureproofing and what do we, as integrators, need to do to make it happen?
First let’s define our terms. What does futureproofing mean in the context of smart building control? I would suggest that the core requirements are: meeting aspirations, assured continuity of supply and simplicity of effecting changes.
The first challenge is to ensure that the installation can satisfy clients aspirations to use the latest technology as it becomes available. The requirements the specify at the outset will surely evolve when faced with the industry’s marketing and in the light of their own growing understanding of what is possible. Right now. it is voice activation that is in high demand. Adding it to an existing system has, perhaps, disproportionately high perceived values to the customer – but the customer is king.
That said, a lot of what is aspired to is really only the front end, the user interface via which the field level devices that actually do the work, actuators, motors, dimmers, switches, thermostats, etc, are commanded. They really should be fairly simple to upgrade. It is the underlying infrastructure that opens the door to future expansion and reconfiguration.
For a system to be futureproof, it is surely a given that it is built on a ubiquitous and harmonised platform that assures there will be continuity of supply. The end user – and indeed integrators charged with maintaining the system – cannot be hostage to the commercial whims of one supplier. It follows that proprietary systems - even when they are thinly disguised as ‘standards’ - are not futureproof. With KNX, there is an assurance that will no happen. Manufacturers of KNX compatible devices, and there are over 400 of them, are attracted by the global marketplace the open communications protocol creates. In return, they must ensure that every KNX product they submit for certification is backwards compatible. Most of the quasi-standards can be integrated into a KNX system and how we do tha is often the topic of conversation between integrators at KNX UK Association networking days, where the collaborative ethos that has always driven KNX is evident.
Simplicity and scalability
Changes and upgrades to installations must be simple. We live in an age where customers expect ‘plug and play’, not ‘rip and replace’. The KNX approach of distributing intelligence and addressing field level devices via robust, inexpensive TP cable makes sense. So while, say, DALI offers on the face of it a good degree of flexibility at the control panel end, significant changes to the lighting schematic are likely to involve costly and disruptive building and remedial work. With a KNX system where you can just drop down from the nearest node on a bus cable. In practice, a popular solution is to couple DALI lighting zones within a building-wide KNX system using readily-available and KNX-certified gateway devices.
At 9600bps, the bus can support over 50 telegrams (instructions to field level devices or feedback from them) per second which is more than sufficient because intelligence is distributed on a KNX network. A KNX installation is further divided into lines and areas, each independent from any others and each with its own capacity of 50 telegrams per second. It is clear that cable bandwidth is not an issue.
While cable remains the backbone of most KNX systems there is, of course, a secure IP connectivity. In fact the KNX language can be spoken across
This all leads to the inevitable conclusion that KNX is unquestionably the best solution for futureproofing intelligent buildings control. The customer has a building that will keep working for them; the integrator has a customer that will keep coming back for more because the price and hassle barriers of continuous improvement are, relatively speaking, negligible.
The key promises implicit in a KNX system are that:
- all the devices they install will work together as intended,
- any one device can be replaced or upgraded, without compromising the whole system,
- expanding and reconfiguring the systems to accommodate the need to change the way a building is laid out and used will always be possible
- any new KNX software developments will be backwards compatible – a device that was addressed by the KNX configuration software (ETS) in, say 2000, can be managed just as easily with, say a 2025 software version and beyond.