The impact of the Internet on controls protocols
Steve Harrison of the Building Controls Industry Association considers how the Internet will impact on building controls and the implications for designers and end-users, with the help of members of the BCIA.
Control of building services is a hot topic because the drive towards greater energy efficiency has placed a focus on better control of equipment such as heating, ventilation and lighting to reduce energy use and ensure that buildings operate effectively and efficiently.
A collection of communications protocols for building services enables a range of different manufacturers’ equipment to sit on the same network. BACnet, LONworks, ModBus, KNX, DALI and more serve as ‘open’ languages for different devices to talk to one another and feed information into the building energy management system (BEMS).
This capability has freed building owners and operators from remaining tied into to a single manufacturer and its proprietary protocol, and allowed for greater integration of control on the central BEMS — making possible for an integrated room-control strategy that incorporates blinds and lighting, for example.
However, the role of these protocols is shifting as we enter what has been termed the Internet of Things (IoT), whereby equipment and devices ranging from HVAC units to wall-mounted sensors will all have their own Internet Protocol (IP) addresses.
One of the main opportunities this presents is use of cloud-based services to store and access data on equipment performance.
Some controls manufacturers have created frameworks for web-based integration. These frameworks have drivers for many protocols and can be assigned an IP address, enabling users to read the information on the Internet or an intranet.
But the next stage will be to aggregate that data and normalise it in the cloud. This makes it accessible to building operators wherever they are and enables them to choose and use the data on their own websites for whatever they want, be that cloud-based control or analytics.
There is a push at the moment from commercial enterprises for employees to use their own devices such as smart phones and tablets to control their environment in the office. This ‘bring-your-own-device’ (BYOD) culture is tailor-made for access to data via the cloud. For this to happen, however, there must be a standardisation of the current disparate communications protocols.
At first sight, this move into the Internet of Things and the need for one protocol, not many, looks like the beginning of a rationalisation of the open protocol we see today.
‘When two devices are talking to each other, you’ve got all sorts of layers in the network,’ says Graham Lewry, product manager at Trend Control Systems. ‘There are physical layers, addressing layers, cable, plugs and connections. So yes, if you’ve got IP-connected devices a lot of this is taken care of.’
However, there is still a requirement for the data to be represented in a way which makes sense for the building energy management system, and BACnet can help with this.
Graham Lewry adds, ‘BACnet is a protocol that was designed for the building-controls network, so it represents things like control loops, analogue objects, sensors and alarms. The Internet of Things will get you so far, and web services are getting better, but I think there still needs to be something that helps people understand what a device is and how it reacts and responds.’
Jim Payne, of Johnson Controls sees the potential for a new protocol to emerge that can bring together the information produced by IP-connected devices: ‘It’s entirely possible that none of the currently established protocols we use now will survive in the Internet of Things and that they could all be superseded.
‘There are new companies coming into the market such as Google for example. They have created a protocol called Weave. It’s IP based and available for smart devices to control home-automated services like lamps and garage doors. It is currently aimed at the residential market, but it’s not a big jump from that to HVAC systems at a commercial level.’
The accessibility and capacity presented by an IP-based future for building-services controls may sound like a panacea to the problems of integration, but it also presents challenges.
One is IT convergence. The skill sets of controls engineers will have to change to possess more knowledge around protocols of programming languages like Java and html rather than control protocols.
A traditional controls installer used to fit valves and sensors and create network loops, but he is now required to make network connections, understand interoperability, connectivity and how a web page works. This will be a key hurdle to overcome as we move towards cloud-based technology, as will the issues around security.
‘The building controls industry has been connecting devices together to create building-wide systems for over 30 years,’ says Jim Payne. ‘That’s a long history of managing and controlling systems in a reliable and secure way. The key is that we control and command all those devices in a network.
‘When we move into to the Internet of Things, where every device is connected, who owns the control and command part? These devices are all peers in a network, so the biggest challenge is how do we, the experts, continue to own the control and command infrastructure of 100 different devices from 100 different manufacturers all operating as peers on an IP-based network.’
Graham Lewry agrees: ‘It’s very easy for someone to put a product on an IP network and have that accessible from anywhere in the world. That’s great from an end-user experience in terms of integrating with the system, but unfortunately, the Internet of Things has a dark side, and there are lots of people out there trying to expose things. So as an industry we’ve taken the good things from the IP world like connectivity and integration — but we’ve also need to remember to take the hygiene and security with us as well. As mentioned earlier you can place an IP device directly onto the Internet, but from an IT-security perspective this shouldn’t be done without the appropriate security settings and systems in place.’
Ultimately, this is the direction the controls industry will go. IP-based networks will make integration cheaper and faster, but upkeep of security and a concerted effort to ensure the right protocols are used must not be left behind in the rush towards the Internet of Things.
Steve Harrison is president of the Building Controls Industry Association (BCIA) and business development manager for Belimo AG.