LON-LAN-WAN. Open control systems and convergence of data networks.
Convergence of data networks can most effectively be achieved through open management systems; integration plays a key role in the process of information exchange.
Before describing the convergence of LON, LAN and WAN technologies, it is worth defining the differences between closed and open systems.
Closed systems
Closed systems are traditionally solutions from individual manufacturers. Such solutions focus on the products of one specific manufacturer and often result in costly maintenance and service, as well as limited options for system expansion.
When using closed systems, compatibility with systems and devices from other manufacturers is limited. All this leads to the emergence of, so to speak, “islands of automation.”
Often such systems have built-in gateways from the manufacturer, which translate or filter information and, thus, support solutions implemented with devices from this company.
The client becomes associated with the equipment and products of one specific company for the entire service life of the system.
Open systems
Many enterprises offer affordable and high-quality service, as well as the ability to expand the system, including subsystems and the field level, at any time.
The presence of a large number of such enterprises makes it easier for systems and devices from different providers to be compatible, providing a wide selection of products. There are currently, for example, more than 700 LonMark-certified products, each of which is compatible with the others, regardless of manufacturer.
Open systems are flexible and provide automation solutions that can be expanded at any time. The client thus remains free in his choice throughout the entire life of the system.
Open systems: definition
Open building automation systems allow the use of devices and systems from different manufacturers, which ultimately provides the user with more flexibility and free choice of products, while providing ease of management and a high level of scalability, as well as reducing overall lifecycle costs and installation costs.
It is also important that when using open systems, expansion and modification of the system becomes easily feasible, easier access to information is provided, as well as more efficient building management.
| Open | Closed |
| Published industry standard | Promoted by one specific company |
| Standard adopted by leading manufacturers | Standard adopted by only a limited number of manufacturers |
| Device from different manufacturers operates in one system | The system can combine products from only one manufacturer or a limited number of manufacturers |
| There is no need for an engineer to ensure communication. Routing technology is usually used | Comprehensive engineering work is required to ensure communication. Typically, proprietary gateways are used |
| Several integrators work on one project | Only one integrator works on a project |
| Multiple types of graphical user interfaces per system | One single graphical user interface per system |
| Various sources for competing compatible products | Single source or limited number of product sources |
| System maintenance by different service departments | System maintenance by only one specific service department |
| Network management system for electrical installations from different manufacturers | There is only one tool or a limited number of tools available that are designed for devices from only one manufacturer |
| Logical flat network architecture | Logical multi-tier network architecture |
| Expandability using transparent routers | Limited expansion options, no routing |
| No need for gateways behind excluding gateways to previously installed systems | Extensive use of gateways to both previously installed and new systems |
| Solutions from independent system integrators are allowed | Solutions from only one single manufacturer are allowed |
What is an “integrated system”
Integration at the building level means nothing more than access to data.
All building functions such as lighting, fire alarms, access control, energy control, heating, air conditioning and ventilation, security, elevator control, telecommunications and meter data recording are interconnected.
Lon technology connects devices into a single control system within a single network, allowing standardized network data to be exchanged between devices and forwarded to a central computer.
Local access is provided via the LAN network via the IP-852 router, oBix XML server or Internet server. Remote control and access to the entire system is carried out over a WAN (Wide Area Network) using enterprise software applications such as, for example, SAP, Oracle or NET Systems.
Data access is key
The modern building manages and integrates data from a huge number of sources. This includes information from alarm systems, control systems, setpoint changes, maintenance planning, event evaluation, quality control and energy management.
Access to this information must be quick and easy. Full integration at low cost is an integral part of the system.
The system must be available to the user, wherever he is, with different access rights defined in each specific case.
The entire enterprise, including branches, must be integrated into the system. All subsystems should work seamlessly, simplifying building management and reducing overall costs.
All these requirements imply one thing: the solution must be a fully integrated system with a constantly evolving platform (such a platform must use the latest technological developments, must be reliable in operation and without restrictions in the foreseeable future).
Such a solution should help reduce system lifetime costs and installation costs, as well as simplify management operations and, importantly, a quick return on investment.
Components: IP-852, Web services and oBIX – LON-LAN-WAN connection
IP-852
IP-852 is LonMark-standardized router for LON/LAN data transmission for peer-to-peer and device-to-devive networks, as well as for tunneling through LAN/WAN. The information transmitted in data packets remains intact and there is no data loss. Data transmission is standardized by CEN, VEA and ANSI.
Web services
An IT standard, Web services enable message transfer from computer to computer and are platform independent: they work on both Mac and PC. Web services are used to transmit browser-independent data such as stock prices, weather forecasts, etc. to the user’s computer screen. The same mechanism allows you to transfer room temperature data, set parameters, access data and dispatch data from the control system to the browser.
oBIX
oBIX (open Building Information exchange) is an OASIS standard that acts as a network server for any type of central computer as long as it accepts XML formatting and can handle SOAP (Simple Object Access Protocol) messages. The message details are filtered and only the translated data remains. oBIX provides standardized data and device profile definitions in XML format. The oBIX standard is supported by LonMark, but is not limited to LON technology. Lonmark International has been focusing on Web services solutions for many years. The LonMark Association has supported the idea of standardizing Web services with oBIX across the industry from the very beginning. In the future, further integration of Web services into open LonMark systems is expected. oBIX was formally proposed by CABA (Continental Automated Buildings Association) and later submitted for further development to OASIS, the Internet standards organization. This was a joint project that LonMark, BACnet and other organizations worked on for almost a year before BACnet decided to withdraw from the project. With a focus on the Internet, oBIX offers a solution that provides a common, XML-based method for data processing and management at the enterprise level.
The following questions and answers are intended to clarify some of the details.
Is oBIX ready to perform its assigned tasks?
Version 1.0 will be published soon and LonMark is preparing to use it. LonMark has converted Standard Network Variables (SNVT) to oBIX XML format. BACnet has not yet shown readiness to support.
Will oBIX replace the direct connection of network management tools to the enterprise level?
oBIX provides general data formatting for monitoring and control, but is not suitable for protocol-level configuration or enterprise-level system provisioning. Network management remains as necessary as ever. However, further developments of this standard do not exclude the possibility of network management functions.
How does oBIX fit into the LonMark — system definition?
LonMark supports enterprise-level data exchange, system-level and device-level interoperability via XML. Translation of LonMark data to XML and vice versa is accomplished using XML schemas and style sheets using a standardized format defined by oBIX. LonMark can use both XML data packets (oBIX) and «tunneled» IP packets according to ANSI/CEA-852 (EN 14908-4).
Why both standards?
Both standards support enterprise-level communications; oBIX provides basic connections, while IP-852 provides a seamless connection to Lon.
A combination of both standards is the ideal solution.
What does this mean for the designer?
Simply put, it provides certain alternatives and choices. As more and more enterprise systems require access to control system data, an increasing number of different interface options are being offered.
Today there are central PC interfaces, embedded touchscreen PCs, control panels and database servers, all requiring the same data provided by a common system architecture.
Just as the IT industry has successfully used the combination of multiple layers of computer data systems, the convergence of LON, LAN and WAN networks provides a cost-effective management solution using standard and all-inclusive competitive equipment.
The use of open systems will save the user from the limitations of using only one specific system architecture, as well as from expensive gateways, and in addition, it will provide more freedom, easier integration of various subsystems and ensure maximum system efficiency.