IP Controllers Change the Building Automation Game

By: Bridgette Lazar, Building Automation Solutions Engineer

I began working in Building Controls during my senior year of college and it has been a constant learning process. When I was getting my degree in mechanical engineering no one really told me about building systems or controls. It is the hybrid field between mechanical systems – essentially, how to connect and control them efficiently. Security, Access, HVAC, energy monitoring, dashboards, analytics, galore! And all facilities need them – laboratories, hospitals, schools, offices, government and private, literally an endless number of possibilities in almost any industry you could dream. There are dozens of large manufacturers, even more contractors, installing these systems, and the controls software and product lines all change and evolve every year. With every new year there is a new version of software, controllers, sensors, IT security requirements, and even more new training needed. With every new launch and update I was promised a way to revolutionize how I do my job designing systems and how the front-end user views controls. With all these promises, I never saw the revolutionary product that I wanted, or I felt like I was promised. Generally, it was a patch or just a small piece of what they were promising – nothing truly revolutionary. This state was at least true, until Schneider Electric came out with the SmartX IP controller midway through last year.

From Home Runs to Daisy Chains

The game changer is the introduction of BACnet IP controllers. The IT world has been making marked improvements on IP communications for years, but the Building Controls industry has been lagging to catch up with these standards set by its information processing cousin – IT. I have seen BACnet IP controllers and some different manufacturers make their stab at IP communications but what made these controllers underwhelming, in my opinion, was the need to wire it to a “home run.”  This makes wiring costs high, large facilities will require lots of managed switches to accept all these IP devices, and I (or someone in the client’s IT department) had to set up a bunch of devices with IP addresses in that managed switch. One of the glorious things about the old-school two-wire communications like BACnet, Modbus, and LON was the ability to daisy chain the controllers together keeping the wiring costs low.

IP Controllers Change the Game

To address the issue with the home runs (and probably my favorite feature of Schneider Electric’s SmartX IP controller line), the devices can be wired in rings, daisy chains, starred, or some combination of these options. See Image 1 to see what I mean. So, what makes this special? If you have a building automation system with wiring that isn’t exactly right or someone accidentally swaps one ethernet cable while replacing a controller, your communication will go down. For anyone who has installed a two-wire (or two wire with a shield), the smallest wire swap could bring down an entire building’s communication. With the ability to do rings, stars, daisy chains, or some combination of these three, failures decrease. If you cut a ring, you get two daisy chains, no devices go down – it is just a different wiring topology. Not to mention that there are even alarms to tell you where the ring failed, so you have time to fix the issue before there is a second failure.

Private Subnetworks

Another nice feature of the SmartX IP controllers are that they can be privately hosted off a private subnetwork, off to the AS’ secondary IP port. As a note, the AS is Schneider’s building controller, like JACE is to my Honeywell Tridium front end. This is great because the AS hosts a private network for all these IP devices to live on, so these devices will never touch your network and drive an IT department insane. This allows for all the benefits of IP devices without having the risk of placing all of these controllers directly on the client’s IP infrastructure. In effect, the same number of IP devices would be on the network as before. The other benefit of utilizing the secondary private IP network created and hosted by the Automation server is it has DHCP mode. You don’t have to assign an IP address to each device to have it communicate, the AS can and will do that for you. This makes changing out controllers and devices quick and easy.

For anyone who has worked with setting up IP addresses for a large facility or office, it isn’t easy. Then add the security protocols, regulations, and properly partitioning your network so that your HVAC system is on its own private sub-networks. This is a necessary and important step, so your networks are properly segregated from each other. The smallest shortcut or incorrect setup can end in a data breach, like the Target breach that occurred a few years ago. I am sorry to call you out Target – I still love shopping in your music free stores! All these concerns are real and valid – lives can literally be on the line. That is why, for almost all HVAC systems, the building controllers and limited IP interfaces are allowed on a private subnetwork set up by the client’s site IP network.

Thanks for Geeking Out with Me

I could literally talk about the technical side of how the IP communications work and all the cool features and the infinite ways to set up a network for days. In fact, my first two attempts to write about the new controllers ended up being a highly technical love letter to how the IP controllers communicate, operate, as well as all things IP. Utilizing IP means you have access to more information, faster. It also gives the building owner and operator built in redundancies that help prevent your network from going down by either malicious network attack or basic maintenance. Building Controls finally just got the facelift that I was promised years ago, and I am extremely excited that controls manufacturers have started to embrace all the facets of IP communications.