LON-LAN-WAN. Open management systems and convergence of data transmission networks.
Convergence of data transmission networks can be most effectively achieved through open management systems, integration plays a key role in the information exchange process.
Before we discuss the convergence of LON, LAN, and WAN technologies, we should first define the differences between closed and open systems.
Closed Systems.
Closed systems are traditionally vendor-specific solutions.
Such solutions focus on the products of one specific vendor and often result in expensive maintenance and service costs, as well as limited options for expanding the system.
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 that translate information or filter it and, thus, support solutions implemented with devices from this company.
The client is tied to the equipment and products of one specific company for the entire service life of the system.
Open systems.
Many companies 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 companies facilitates the task of compatibility of systems and devices of different providers, providing a wide choice of products.
At the moment, for example, there are more than 700 LonMark-certified products, each of which is compatible with others regardless of the manufacturer.
Open systems are flexible and provide automation solutions that can be expanded at any time.
The customer thus remains free to make his or her choice throughout the entire life cycle 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 ensuring ease of management and a high level of scalability, as well as reducing overall life cycle costs and installation costs.
It is also important that when using open systems, expansion and modification of the system become easy to implement, easier access to information is provided, as well as more efficient building management.
| Open | Closed |
| Published industry standard | Promoted by one specific company |
| The standard is accepted by leading manufacturers | The standard is accepted by only a limited number of manufacturers |
| Devices from different manufacturers operate 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 provide communication. Routing technology is usually used | Complex engineering work is required to ensure communication. Proprietary gateways are usually used |
| Multiple integrators working on a single project | Only one integrator working on a project |
| Multiple types of GUIs per system | Single GUI per system |
| Different sources for competing compatible products | Single source or limited number of sources of products |
| System maintenance by different service departments | System maintenance by only one specific service department |
| Network management system for electrical installations from different manufacturers | Only one tool or a limited number of tools available, which are designed for devices from only one manufacturer |
| Logical flat network architecture | Logical multi-tier network architecture |
| Expandability via transparent routers | Limited expandability, no routing |
| No need for gateways except for gateways to previously installed systems | Extensive use of gateways to both previously installed and new systems |
| Independent system integrator solutions are allowed | Only solutions from 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 alarm, access control, energy control, HVAC, security, elevator control, telecommunications and meter data recording are linked.
Lon technology connects devices into a single control system within a single network, providing exchange of standardized network data between devices and sending it to the central computer.
Local access is provided via LAN via IP-852 router, oBix XML server or Internet server.
Remote control and access to the entire system is provided via WAN (Wide Area Network) using enterprise software applications such as SAP, Oracle or NET Systems.
Access to data is key.
A modern building manages and integrates data from a huge number of sources.
This data includes information from alarm systems, control systems, setpoint management, maintenance planning, event evaluation, quality control and energy management.
Access to this information must be fast 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 must work harmoniously, 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 limitations in the foreseeable future).
Such a solution must help reduce the costs over the life cycle of the systems 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 a LonMark-standardized router for LON/LAN data transmission for peer-to-peer and devive-to-devive networks, as well as for LAN/WAN tunneling. The information transmitted in the data packets remains intact and there is no data loss. Data transmission is standardized by CEN, VEA and ANSI.
Web Services.
As an IT standard, Web Services provide computer-to-computer messaging and are platform independent: they work on both Macintosh and PC.
Web services are used to transmit data such as stock prices, weather forecasts, etc. to the user's computer screen independently of the browser.
The same mechanism allows the transmission of 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 and acts as a network server for any type of host computer as long as it accepts XML formatting and can process 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 involved in Web services solutions for many years. LonMark has supported the idea of standardizing Web services with oBIX in the industry from the very beginning.
Further integration of Web services into LonMark open systems is expected in the future.
oBIX was formally proposed to CABA (Continental Automated Buildings Association) and later transferred for further development to OASIS, the Internet standards organization.
This was a collaborative project between LonMark, BACnet and others for nearly a year before BACnet decided to pull out of the project.
With a focus on the Internet, oBIX offers a solution that provides a common, XML-based method for enterprise-wide data processing and management.
The following questions and answers are provided to clarify some of the details.
Is oBIX up to the task?
Version 1.0 is coming soon and LonMark is preparing to use it. LonMark has converted the standard network variables (SNVTs) to the oBIX XML format.
BACnet has not yet indicated support.
Will oBIX replace direct connectivity of network management tools to the enterprise level?
oBIX provides a common data format for control and management, but is not suitable for protocol-level configuration or for 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 compatibility, and device-level compatibility via XML.
Translation of LonMark data to and from XML is accomplished using XML schemas and stylesheets 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 connectivity; oBIX provides the basic connections, while IP-852 provides seamless connectivity to Lon.
A combination of both standards is an ideal solution.
What does this mean for the designer?
Simply put, it provides certain alternatives and choices.
With more and more corporate systems requiring access to control system data, there are also more and more different interface options available.
Today, there are central PC interfaces, embedded PCs with touch screens, control panels and database servers, all requiring the same data provided by a common system architecture.
Just as IT successfully combines several layers of computer data systems, the convergence of LON, LAN and WAN networks provides a cost-effective control solution using standard and competitive equipment.
The use of open systems will free the user from the limitations of using only one specific system architecture, as well as expensive gateways, and will also provide more freedom, easier integration of various subsystems and ensure maximum system efficiency.