System Integration

Princeton Engineering Services is proud to offer fully interoperable, advanced control system solutions, utilizing LONWORKS® and BACnet based open-protocol control products. PES works with owners, vendors, and contractors to provide System Integration services to create a software/hardware platform to allow the owners to install multiple vendors' controls throughout their various buildings.

Princeton Engineering Services open system integration is designed to:

• Allow systems to seamlessly share information. The sharing of information reduces the total number of devices resulting in an overall decrease in installed cost. For example, a single room occupancy sensor notifies the lighting control system, HVAC system and security system of the presence of occupants. Each respective system would take the appropriate action based on this information, i.e.; the lighting system would index the lights on or off, the HVAC system would impose setback temperatures (if the area was vacant), and the security system would provide alarm annunciation if an intruder was detected during unoccupied periods.
• Capitalize on system infrastructure. Installing several independent systems creates duplication of devices as well as infrastructure. From the above example, a single room occupancy sensor takes the place of three. Independent, non-integrated systems also utilize individual user interface PCs, and communication risers all performing discrete individual tasks. Once all system components operate from a common networking platform and "speak the same language", a single user interface and network infrastructure can serve all building functions.
• Eliminate proprietary systems and promote competitive pricing. Building owners and developers can take advantage of competitive forces when multiple vendors and suppliers are bidding a project. Unfortunately, when a proprietary system is installed this purchasing power usually disappears after the initial installation. Often a sole source vendor can demand his price and may even provide the customer with less then satisfactory service. Utilization of open protocols allows owners to continuously competitively purchase system expansions and service

Although many standard protocols have been proposed, BACnet and LonWorks have emerged as the two that are being widely accepted by facility owners, manufactures and consulting engineers in the Building Controls Industry.

BACnet was developed by the American Society of Heating Refrigeration and Air conditioning Engineers (ASHRAE) to allow different systems to share information and allow for a single seat user interface. BACnet is "a data communication protocol for building automation and control networks." A data communication protocol is a set of rules governing the exchange of data over a computer network. The rules take the form of a written specification that spells out what is required to conform to the protocol, everything from what kind of cable to use to how to form a particular request or command in a standard way. The rules relate specifically to the needs of building automation and control equipment, i.e., they cover things like how to ask for the value of a temperature, define a fan operating schedule, or send a pump status alarm. Released in 1996 BACnet has been adopted by mechanical equipment and control system manufacturers, and has resulted in successful integration for many projects.

LonWorks was developed by Echelon Corporation in 1991. The LonWorks technology is based on the principle of creating intelligent, networkable devices, which can be networked in a flat architecture scheme. Each intelligent device is manufactured with a Neuron chip; an integrated circuit that combines the communications protocol, microprocessor, operating system, and flexible I/O. Devices containing the Neuron chip and having been configured in accordance with the LonMark Association* guidelines, can harmoniously coexist and share information on a control network. This allows the devices to become a control network without the dependency on centralized control panels or communication gateways. Thousands of LonWorks based devices have been manufactured for buildings, factories, transportation, and home applications, facilitating the installation of many successful multi-vendor integrated systems.

* The LonMark Association is comprised of manufactures, end users, specifiers and integrators, develops guidelines to allow Lon based products to interoperate.

LonMark FAQ

1. What is the LonMark's Association's definition of interoperability?
   LonMark Interoperability means the easy integration of products from multiple vendors without the need for custom hardware or software.
    
2. What is a control network?
   A control network is a group of devices that are networked together to sense, monitor, communicate and control. In some ways, a control network resembles a data network (such as a LAN). Whereas, data networks consist of computers networked together, control networks consist of sensors actuators and controllers networked together. Similar to data networks, control networks consist of devices attached to various communications media, connected by routers that communicate to one another using a common protocol. Network management software allows administrators to configure and maintain their networks. In control networks the components are optimized for the cost, performance, size and response characteristics of control applications to enable networks to extend into a class of applications that data networking technology cannot reach.
   Control networks can range in sophistication from small networks embedded in machines to large networks with thousands of nodes controlling fusion lasers, paper manufacturing machines, building automation systems, semiconductor tools and diffusion furnaces. Buildings, trains, airplanes, factories and hundreds of other entities and processes can use control networks.
   Before the advent of control networks, most control systems required thousands of feet (even miles) of expensive wiring to connect dumb components to a custom-programmed central controller. Expansion required costly rewiring and custom programming. These systems were vulnerable to failure of the central controllers - a single point of failure.
   Control networks have changed this. By distributing processing among all of the control devices on the network, the central point of failure is eliminated. By allowing free flow of information between devices, control is improved and new applications are enabled. Additionally, plugging in new devices can expand control networks.
    
3. What is a LonWorks® control network?
   LonWorks is a complete, open, off-the-shelf networking technology platform for designing and implementing interoperable control networks. LonWorks does much more than integrate a myriad of devices and control systems. In contrast with traditional networks, it offers manufacturers and builders a single, cohesive, interoperational control system that does not depend on one proprietary vendor or require costly customizations.
   Additional information on the LonWorks technology can be found at http://www.echelon.com/products/lonworks/default.htm.

    

4. Why is Interoperability so important to control networks?
   With interoperable control devices, end-users and network integrators can purchase devices "off-the-shelf" from different manufacturers. Plugging in new interoperable devices, that work together regardless of manufacturer, can easily expand control networks.
    
5. What are the LonMark Interoperability guidelines?
   The LonMark Interoperability Association design guidelines help manufacturers build interoperable LonMark products based upon LonWorks technology. Within Association Task Groups, LonMark members develop application specific functional profiles. The profiles precisely layout the network interface for a particular controls function. Functional profiles ease the specification process and enhance interoperability without compromising the ability of specifiers to call for unique capabilities, or the ability of manufacturers to differentiate products.
   LonMark profiles are developed through a rigorous analysis and approval process that includes a cross-functional review to ensure that profiles not only interoperate within an individual subsystem, but also provide interoperability with other subsystems within a building. For example, the Fire profiles incorporate an Alarm network variable that is an essential characteristic of a fire system but is also available for use anywhere else in the building; for coordination of elevator control, damper control and exit lighting.
    
6. What does it mean if a product is LonMark certified?
   Products that have been verified to conform to LonMark interoperability guidelines are eligible to carry the LonMark logo. The LonMark logo is an indicator that a product has completed the LonMark conformance tests and has been designed to interoperate across a LonWorks network.
    
7. What are the benefits of LonMark certified products?
   The availability of LonMark products provides end-users, system integrators and equipment specifiers the benefits of open interoperable multi-vendor systems:
    
   • Choice of vendors
   • Use of third party tools
   • Easy integration
   • Easy additions and changes

   Where once end-users were locked into lengthy and costly service and upgrade agreements from a single vendor, they can now implement control systems using LonMark devices from multiple vendors picking and choosing devices that best suit their needs knowing they can be easily integrated.