Issues in Developing Open Source Licensing Tool for Controllers in the Context of BA (Building Automation)

Transcription

1 Issues in Developing Open Source Licensing Tool for Controllers in the Context of BA (Building Automation) Shah Ujval M Rajasekhara Babu M Khalid M.Tech computer science, SCSE Assistant (S.G) Professor, SCSE Director, SCSE VIT University, Vellore VIT University, Vellore VIT University, Vellore Tamil Nadu, India Tamil Nadu, India Tamil Nadu, India shah.ujval@gmail.com mrajasekharababu@vit.ac.in mkhalid@vit.ac.in Abstract -- Over the past ten years building owners, Managers and consulting engineers from the different Manufacturers/Vendors have become the increasingly frustrated by incompatibilities and limited Mechanism for the integration of building automation and control systems(bas)[1] because a site may have BAS equipment from multiple manufacturers in the field. A controller comes with different functionalities. Some of the functionalities will be locked down by the manufactures. There are times when site engineer need to lock or unlock the particular functionality of the controllers, called licensing. As Controllers are part of BAS, there are at present three issues in Developing open source licensing tool, and they mainly concentrate on BAS integration. They are Integration between BAS and existing Enterprise applications, integration of widely used open protocol standards (e.g. BACnet or LonTalk), and integration of subsystems (HVAC systems, fire safety systems, life safety, lighting systems [11]) of BAS [14]. Though today many solutions are available, Integration of diverse and heterogeneous BAS systems is a challenge. The paper describes the issues in developing open source licensing tool and how to overcome these issues. Keywords: Building Automation and control Systems (BAS); System integration; licensing; I. INTRODUCTION A building automation system (BAS) is an example of a distributed control systems. It describes the functionality provided by the building control systems, which is a computerized, intelligent network of electronic devices (mostly sensors, actuators and controllers), designed to monitor and control the mechanical and lighting systems in a building.bas core functionality keeps the building climate within a specified range, provides lighting based on an occupancy schedule, monitor systems performance and device failures and provides and/or text notifications to building engineering staffs. The BAS functionality reduces building energy and maintenance costs when compared to non-controlled building [18] Building automation systems are traditionally concerned with the control of heating, ventilation and air conditioning as well as lighting systems. With the advancement of technology, Modern building automation systems often called as intelligent buildings consist more than 30,000 components (e.g. sensors, actuators, and controllers).one of the main concern of BAS is how to integrate building automation controllers (as found in HVAC systems, lighting systems, security systems, fire safety systems, etc.) manufactured by different companies to communicate and share data with each other. Still some Manufactures are using Proprietary protocols for communication.proprietry protocols were an excellent tool in the 70s and 80s for BAS applications but were excessively expensive. This high cost spurred the search for greater efficiencies and less expensive alternatives. This led to the development of the BACnet [6-7] (A data Communication Protocol for Building Automation and Control Networks) completely non-proprietary open communication software standard by ASHRAE [5] and LonWorks [9]. Open system technologies have changed how the building automation industry conducts business. The relationship between owner, system integrator and manufacturer has been changed. Many owners are now taking advantage of Open system technologies to create a total building control network that encompasses every building system [3].Virtually all BAS manufactures have already adopted BACnet as the platform of choice at the system, or network level [5]. A. What is licensing? Licensing means to enable or disable some functionality of the controllers. Controller comes with different functionalities and some functionality might be locked down by manufactures. There are times when site engineer need to unlock the some of the functionality of the controller and to enable/disable certain functionality of each controller manually is a tedious process. 485

2 B. How we can achieve it? To enable/disable some functionality of the controllers, a controller requires an Unlock code. As BAS site contains several subsystems (HVAC systems, lighting systems, fire safety systems, etc), site engineer need to make a separate request for each controller in a different subsystem to enable/disable certain functionalities. This is the complex process and there are certain issues present in BASs subsystem integration. C. License file Format As Paper aims to develop open source licensing tool, a common file format should be followed. Table 1 shows the Parameter that will be the part of a XML File format. TABLE 1: A COMMON XML FILE FORMAT Field Type Comment SiteID String Unique site identifier SubsystemID String Unique subsystem under site (HVAC, lighting, Security, fire Alaram,etc) Unlock code String Present Only in the File generated by server Error description String Contains human readable description of the current status of the device entry D. Example of license file generated by tool Site engineer make a request of controllers to enable/disable functionality through tool. Example file generated by tool looks like this. <?xml version="1.0" encoding="utf-8" standalone="yes"?> <! Request file generated by Tool--> <BASsite> <SiteID> BAS12345</ SiteID> <SubsystemID>BASsite1234</SubsystemID> <SerialNumber> </SerialNumber> No licence request made yet generated by Tool </ErrorDescription > <SubsystemID>BASsite5678 </SubsystemID> <SerialNumber>ABCDEFGHIJ</SerialNumber> No licence request made yet generated by tool </ ErrorDescription > </BASsite> E. Example file Generated by the Server Once generated, server will put an appropriate unlock code in to the controllers. And controller will try to enable/disable particular functionality. Success/Failure can be seen in the file generated by server. <?xml version="1.0" encoding="utf-8" standalone="yes"?> <! Request file generated by Tool--> <BASsite> <SiteID> BAS12345</ SiteID> <SubsystemID> BASsite1234 </SubsystemID> <SerialNumber> </SerialNumber> <Unlock>XXXXXXXXXXXXXXXX</Unlock> Success - ABC functionality is enabled </ErrorDescription > <SubsystemID> BASsite5678 </SubsystemID> <SerialNumber>ABCDEFGHIJ</SerialNumber> <Unlock>XXXXXXXXXXXXXXXXX</Unlock> Failure Unlock code not matches or Device Id is wrong </ ErrorDescription > </BASsite> II. PROBLEMS IN DEVELOPING OPEN SOURCE LICENCING TOOL IN BAS Although the sophistication and flexibility of networking and communication technologies in general have been increasing geometrically, controls systems for buildings have carried forward a legacy of proprietary thinking which has impeded the natural migration of many of the benefits of open networking technology in to building systems. Through accident or intent, building automation and control systems have simply failed to embrace true open system concepts effectively for building owners [1]. 1. In early 80s, there was no such protocol which could satisfy BAS industry s needs. But Advancement of BACnet and LonWorks (Open system technologies) seems to satisfy need of the building automation systems. Nowadays, BAS manufactures always need to develop the products which support one or more of the Open standard protocols that are available. But the main concern or often it is difficult for BAS to integrate the products which adopt different protocols [14]. As we have different subsystems (HVAC systems, Lighting systems, safety systems, security systems) in BAS. Consider different building automation devices, each with different functionality and/or from different manufactures. In 486

3 Fig. 1, the solid color portion of each symbol below is dedicated to the devices specific function within the building HVAC, Lighting, Security, life safety, etc. Even though Open System Technologies BACnet and LonWorks have gained their success in commercial BAS markets still some vendors are providing Proprietary protocol solutions. Fig 1. Presents the proprietary protocol solutions. So, Licensor application needs to make different requests according to controllers present in the different subsystems of BAS. It s not easy for tool to create request based on different proprietary communication protocol. Figure 1: A proprietary protocol solution 2. The present BAS are separated from IT (information technology systems), and BAS is an isolated island of information. Now most building owners, Managers and tenants hope to integrate BAS with their own enterprise application systems [13-14], and then BAS become one part of the enterprise information system [14]. The problem here is BAS manufactures has to pay more attention to develop products which can support TCP/IP network protocol (e.g. BACnet/IP of BACnet [12] and DDE of LonWorks). These technologies can realize interconnection and interactive operation between BAS and desktop applications. Also the traditional integration of building automation systems are more concerned about interactive operation among the systems. So the System s Coupling is strong. And the goal of real-time and seamless integration in BAS industry looks to fed away [14]. Our aim is to make system loosely coupled. 3. The term intelligent Building has become more popular in the 21 st century. Based on the gathered data about how the building energy is used, intelligent buildings can make decisions on how to control their corresponding subsystems such as lighting, temperature, security, and even window shade systems [18]. Issue here is products of HVAC systems, lighting system, security system and fire alarming system may adopt different protocols or be produced by different manufacturers, and these products are incompatible and can t be connected to each other.bas systems can t be integrated with enterprise applications conveniently [14] So, how licensing application makes an intelligent decision over here is big question. Controllers might need to enable/disable some functionality by their own according to data gathered from the environment. 4. BAS industry is still evolving, the development step of IT moves faster than BAS and gap between them becomes larger than ever [14]. Still many buildings are using Legacy systems installed years ago. Maintenance cost of such a building is likely to be high. And the great deal here is what happens if they want to include some new system in the Building (e.g. Security system). Integration of existing system and new system is complex process. Over the last four decades, growth and evolvement of IT infrastructure is tremendous and BAS systems need to step up in accordance with the growth of internet technologies. With the development of internet technologies in recent years, web services technology becomes the developing trend, Web services make it easier to integrate enterprise application systems with building automation systems and integrate BAS subsystems which adopt different standardize protocols than ever before [14]. III. CORRESPONDING SOLUTIONS There are different ways to integrate products made by different manufacturers but it s difficult. One of the possible solutions is to make a single front end system which knows the proprietary communication technique of each different system, and effectively bringing their difference in the sofatware.this approach requires cooperation of multiple manufactures. Practically these systems are very costly to implement and support, as the various systems evolve and change independently [6]. Another method involves defining a common protocol between centralized front end and individual gateways to proprietary systems. This approach has also proven to be costly, and was not really supported by vendors [6]. There are several solutions available in the market for the BAS integration. Next few paragraphs will show some of them. Every solution has its pros and cons. A. solution is based on Open system Protocols (such as BACnet and LonWorks) Today, we have several options to replace Proprietary Data Communication protocol used in BAS. At present, 487

4 Shah Ujval,M Rajasekhara babu,m Khalid, Int. J. Comp. Tech. Appl., Vol 2 (3), BACnet [6-8], LonWorks [9] and KNX [10] protocols have been widely accepted and used in BAS industry. So BACnet, Lon Works, and KNX protocols have got great success and development in past one decade, and they play more and more important roles in BAS industry. But of the different solutions present for integration of building services, BACnet is unofficially becoming the world standard (Frost and Sullivan s Conclusion). BACnet is an ANSI standard, ASHRAE standard, CEN standard, Korean National Standard, Arabic standard, and an ISO standard[5]. environment[15-17].today, there are over 245,000 instances of the Niagara Framework deployed worldwide. Fig. 3 represents the solution based on Niagara Framework. It shows how Niagara can be helpful to covert proprietary communication protocol to common object model. So, Licensing application need not have to create different Request for each Controllers Present in the site based on the manufacturers. Fig. 2 shows the solution respect to open standard protocol. The BACnet concept is to replace the communication portion of each device with a common, standard set of communication rules a common language so that each device looks the same on the wire. So, Licensing Tool need to create only one request for all types of controllers present in the BAS regardless of Manufactures and vendors. Figure 3: Solution With respect to Niagara Framework C. BAS system And Integration Technology Based on Web Services Next solution is based on integration between BASs and enterprise applications based on web services proposed by Jianho Bai, Hong Xiao, Xianghua Yang, and Guofang Zhang [14]. Figure 2: Open standard Protocol solution (BACnet) B. Solution based on Niagara Framework The problem here is having more than one Open System Protocols makes User confuse to choose between which protocols to use. Because again each protocol has its own advantage and disadvantage. Some people claims that BACnet is better than Lon Works and Others Vice Versa. We can still integrate different open standards such as BACnet [6-8], LonWorks [9], KNX [10] and Modbus by means of Niagara software Framework. The Niagara Framework [15-17] is a software platform that integrates diverse systems and devices regardless of manufacturer, or communication protocol into a unified platform that can be easily managed and controlled in real time over the Internet using a standard web browser. By integrating today's diverse building systems such as environmental controls, security, lighting, energy, video, fire and life safety, Niagara is creating better buildings ones that are smarter, use less energy, are more efficient, have lower operating costs, are safer and contribute to a sustainable Web services have a capability to provide good integration. At Present web services technology is the popular integration methods [14].this standard basedtechnology enables different Web Services to communicate with each other regardless of hardware and operating systems, Act as an ideal integration tool. The integration of web services is easy and less expensive. Web service can also help us realize the seamless and real-time integration between BASs and among BAS subsystems which adopt different standardized protocols or have different functions [14]. Fig. 4 shows the solutions respect to web service integration. Original sketch map includes three types of integration [14]. This solution mainly concentrate on the integration among BAS subsystems which adopt BACnet protocol, LonTalk protocol or other communication Protocols. Web service can be installed in controllers. BAS based on Web Services is not to replace the standardized Communication protocols which have been widely used in industries. It is use to realize higher level integration. 488

5 So, Licensing application need not have to create different Request for each Controllers Present in the site based on the manufacturers. Figure 4: solution with Respect to Web service integration IV. CONCLUSION Solutions presented above seem to solve the problem for a while but integration of heterogeneous systems is still a big issue worldwide. Though they are many solutions and alternative to this problem but no solution seem to provide a flexible, Scalable, Robust and Secure solutions. Every solution has its pros and cons. Introducing Open standards (such as BACnet, LonWorks), Niagara Framework, and a Web Service Technology in to BAS domain will seem to change the situation that BAS is an information island, and they have succeeded to some extent. And to develop an open source licensing tool seems to be possible for now. Building systems: BACnet, in Proc. Of the 1999 IEEE International Conference on Control Applications, Hawaii, USA, Vol. 2, pp , August [9] Control Network Protocol Specifications, ANSI/EIA/CEA 709.1, 1999 [10] KNX Specification, Konnex Assoc., Diegem,Belgium, 2009, Ver [11] Newman, H.M., Direct digital control of Building Systems: Theory and Practice, John Wiley & Sons. Inc., New York, [12] R.A. Fellows, "Connecting BACnet to the Internet, Heating/Piping/Air Conditioning HPAC Engineering, Vol. 72, No. 3, pp , March [13] L. Mark, An Owner s perspective of BAS and BAS Integration, Heating/Piping/Air Conditioning HPAC Engineering, Vol. 75, No. 7, pp , [14] Jianbo Bai, Hong Xiao, Xianghua Yang, Guofang Zhang, Study on Integration Technologies of Building Automation Systems based on Web Services, ISECS International Colloquium on in Computing, Communication, Control, and Management, 2009 (CCCM 2009), Vol. 4, pp , August [15] The Niagara Framework: Measuring Up to Open, Available from: white_papers/openwpfinal.pdf [16] The Niagara Framework, available from: _services/frameworks [17] A Comprehensive Software Platform Designed to Create Smart Device Applications An Overview of NiagaraAX, available from: [18] Wenqi Guo, Manchu Zhou, An Emerging Technology for improved Building Automation Control, Proc. Of the 2009 IEEE International conference on Systems, Man, and Cybernetics, San Antonio TX, USA, Vol. 2, pp. 337, October V. REFERENCES [1] Fisher, D.M., July "BACnet & LonWorks: A White Paper" available from: [2] Fellows, R. A., March "Connecting BACnet to the Internet" HPAC - Heating/Piping/Air Conditioning. Vol. 72, No. 3, pp [3] Investigating Open Systems Comparing LonWorks and BACnet available from: InvestigatingOpenSystems-2006-At%20a%20Glance.pdf [4] James Piper, November 2007, BACnet, LonMark and Modbus: How and Why They Work available from: LonMark-and-Modbus-How-and- Why-They-Work 7712 [5] State of the Art for Building automation system in hospital healthcare, available from: State_of_the_Art_-_Hospital_BAS.pdf [6] BACnet, [7] ANSI/ASHRAE Standard BACnet: A Data Communication Protocol for Building Automation and Control Networks, American Society of Heating, Refrigeration, and Air conditioning Engineers Inc. Atlanta, GA. [8] Haakenstad, L.K., The Open Protocol Standard for Computerized 489