Open Control Systems and Data Networking Convergence

By Ron Bernstein

Data convergence is the overall connecting of building control devices by allowing formerly non-interactive agents to share and use common information. Convergence can be best achieved through open control networks as integration is the key to information exchange. Let’s begin by explaining the difference between open and closed systems before describing networking convergence between LON, LAN, and WAN.

Closed Systems
Traditional closed systems are single vendor solutions with restricted sub-system expansion and a limit on the number of service providers, all of which often lead to costly service and system expansion,. Closed systems tend to restrict interoperability with other vendors/systems, thus limiting choices and creating “Islands of Automation”. The outcome of all this is that owners are locked in for the life of the system!

Open Systems
Multiple vendors enable affordable and economical service and system expansion, as well as sub-system and device-level expansion at any time. Full choice of service providers facilitate interoperability with other vendors/systems and allow a plethora of choices. Open systems are flexible, expandable automation solutions. All this empowers owners to retain the freedom to choose the best products for their needs throughout the lifetime of the system!

Open Systems Defined
Open building systems are created using the products and systems from multiple vendors that, in the end, offer greater flexibility, easier management, higher levels of scalability, and lower life cycle costs. Additionally, open systems offer greater choices of vendors and suppliers, lower energy costs, lower installation and life cycle costs, and allow easier additions, moves, and changes, as well as better access to information and greater control over the facility.

Open Versus Closed – An overview

What is an “Integrated System”?
Integration at the building level means access to information. All the buildings’ services, such as lighting, fire, energy, HVAC, security, and metering and monitoring services are interconnected. It can be as simple as a sensor sensing motion in a space and telling the lighting system to turn on; the most fundamental control system. Add a bit more complexity and have the same sensor also adjust air flow in the room based on occupancy level. Take it a step further and have the sensor report occupancy to the security system. This adds layers of control and interoperability between the lighting, HVAC, and security systems. This is where LON-LAN-WAN become key.

LON acts to connect devices in a control system into a single cohesive network sharing standard network variables, which are freely exchanged between devices and then sent to a PC and the Internet. LON posts information for anything in the network to utilize. Remote access is achieved via the LAN using an IP-852 router or oBIX XML server or Web server. The WAN offers remote monitoring and control of the whole system, dovetailing into enterprise solutions such as SAP, Oracle or IBM systems for example, allowing for flexible access to the system.

Access to information is THE KEY
Information is power. Modern buildings must manage and integrate information from a range of sources including alarming, monitoring, overrides, maintenance scheduling, quality control, energy management, and enterprise-wide consistency. Access to this information must be simple, quick and easy. It must offer complete integration and reduce costs. It must be available on the network, at home, or on the road with different access levels for different personal needs. The whole business enterprise must be integrated including all remote locations. All subsystems must work together and it must simplify facility management while reducing costs.

All of these demands mean the solution must be a fully integrated system with a platform that will grow over time, that isn’t limited today—or in the near future—that uses the latest advancement in technology, but is proven to work (no one wants to be a guinea pig) and it must reduce installation and life cycle costs, simplify management operations and provide a positive return on investment.

The components: IP-852, Web Services & oBIX — The LON-LAN-WAN Link IP-852 IP-852 is a message routing standard developed by LONMARK for LON to LAN message transfer, offering a peer-to-peer network, device to device messaging and enabling tunnelling via LAN/WAN. All data packet information remains intact so nothing gets lost and it is supported by CEN, EIA, and ANSI.

Web Services
Web Services enable computer-to-computer message transfer and is platform independent –MAC, PC, SQL, SAP, Oracle, Sybase, etc. It is the IT standard.

oBIX
oBIX is the OASIS standards initiative for building data information exchange, acting as a network server to any computer host data transfer. Message details are stripped out, and only the translated data remains. oBIX supplies the need for standard data and device profile definitions at the XML layer. It is LONMARK supported, but it is not limited to LON.

In fact, LONMARK International has been involved with Web Services solutions for many years, and has supported the “oBIX” effort to standardise Web Services on an industry-wide scale since the group’s conception. In the future, we expect the continuation of Web Services integration into LONMARK open systems.

oBIX stands for open Building Information eXchange, and was formally proposed within CABA, the Continental Automated Buildings Association. Chosen for its Internet-centricity, oBIX provides the solution to the need for a common XML-based method of enterprise-level data acquisition and control.

The following four Q & A’s should help clarify any remaining uncertainties regarding LON, LAN, and WAN:

Q: Is oBIX now ready to face the challenge?
A: Version 1.0 is available now for download and review and LONMARK is currently converting the SNVTs (Standard Network Variable Types). Various vendors are implementing solutions based upon this effort. Version 2.0 is also in development which expands the scope and ability. For more information see http://www.oasis-open.org .

Q: Does oBIX replace a direct LNS® connection to the enterprise level?
A: oBIX provides common data formatting across disparate systems for monitoring, but it cannot do protocol-level configuration, nor enterprise-level system provisioning. Proposed future versions may incorporate additional management functionality. LNS continues to provide seamless management, monitoring and control within a LON system. oBIX has the potential to reach outside of LON into other solutions.

Q: So how does oBIX fit in with the LONMARK system definition view?
A: LONMARK supports enterprise-level data sharing, system-level interoperability, and device-level interoperability via XML. This translation of LONMARK data types to/from their XML equivalents is achieved using XML Schema and Style Sheets into a standardized format, like oBIX. LONMARK can use XML packets (oBIX), or ANSI/EIA/CEA-852 tunnelled binary IP packets: “IP-852.”

Q: Why use both?
A: Both provide enterprise-level connectivity, where oBIX provides basic interfacing, and IP-852 provides seamless LONWORKS. A combination of both provides the ideal solution.

So finally, make sure you demand an open control system. To ensure openness, verify that you will not be locked in on any level of the system. Encourage multi-subsystem integration for maximum efficiency. Start from a good open specification framework and learn the technologies, options, and market directions. After all, freedom of open information exchange is empowering.

For Information contact:
Ron Bernstein
LONMARK® International
550 Meridian Avenue
San Jose, CA 95126
Tel: +1 408 938 5266
Fax: +1 408 790 3838
Email: [email protected]
http://www.lonmark.org