1984). One of the most challenging house industry the number of high- Real-time tasks of the modern greenhouse grower tech greenhouse operations is con- Monitoring of is to manage the large amount of data stantly increasing. It is becoming volume and to process it in such a way increasingly important to monitor the Greenhouse that important information is not over- system 24 h per day by a wider range of looked because of an overload of the people who have an interest in the Climate Control available data (Ehler and Rystedt, information. In university greenhouse 1990). This makes information man- operations, researchers and students Using the agement an important area of research alike are interested in closely following and development in greenhouse envi- the experiments, but without having Internet ronmental control. Once the signifi- to be physically present all the time. cant information has been identified Furthermore, the general public might and retrieved, it may be necessary to also have an interest in climatic infor- Niels Ehler and provide a broad range of users a simple mation, not just from inside the green- Jesper M. Aaslyng way of accessing these data. The Inter- houses but also from the weather net is an obvious candidate as a chan- station connected to the climate com- nel for distributing this information. puter system and from ongoing re- So far data access for greenhouse com- search. ADDITIONAL INDEX WORDS. environmen- puters has only been possible using The objective of the project was tal control computer, HTML, remote access software packages, but to develop a system that could dy- databases, dynamical web integration this requires installing of licensed soft- namically generate a web application SUMMARY. The possibility of con- ware on both the client and the server to integrate real-time greenhouse con- structing an Internet application that PC. trol information. The web site should would enable greenhouse users to If greenhouse information can be work reliably to supply greenhouse track climate and control parameters directed to a web site, then any person, users with continuous climatic infor- from any Internet-connected com- regardless of having special technical mation. The site should enable the puter was investigated. By construct- skills, can gain access with a standard user to quickly gain access to the most ing a set of HTML-templates, Internet browser. The greenhouse is a critical data describing the greenhouse dynamic information from the dynamic system where important sys- climate and the status of the control control-system databases was inte- tem states change every few minutes. functions. Furthermore, the applica- grated in real-time, and was uploaded to a common net-server by automatic Therefore it is necessary that the con- tion should be readily tailored to suit generation of web pages using tents of the web site should be auto- software developed during the project. matically updated on a similar Fig. 1. Outline of the total system Good performance, reliability and time-scale, to provide the user with the structure showing the different security were obtained and the current climate and status of the tech- system components and how they technology proved to be an efficient nical systems. In the European green- relate to each other. way of supplying a broad range of users not only with climatic data but also with results from ongoing research. reenhouse climate con- trol traditionally has been G a topic where process regula- tion has been the main focus. The introduction of computers and digital technology in the early 1980s has greatly improved the control possibili- ties and significantly increased the amount of data acquired by standard greenhouse operations (Hashimoto et al., 1980; Udink ten Cate and Challa, Section for Horticulture, Department of Agricultural Sciences, The Royal Veterinary and Agricultural Uni- versity, Thorvaldsensvej 57, DK 1871 Frederiksberg C, Denmark. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact. The authors thank Allan Holm Nielsen for his invalu- able assistance in designing the graphical elements integrated in the web application described in this paper. ● October–December 2001 11(4) 639 T&P 639 9/5/01, 12:01 PM TECHNOLOGY & PRODUCT REPORTS Microsoft Windows information. This was done by send- 95 operating system ing a request to BipsArch, the green- and the DGT- house server program to begin Volmatic ECC-stan- collecting the data from the climate dard software computer system needed by the web Superlink (DGT- application. Volmatic, 1988). The web-application program Superlink included a (CYBGR4) processed a list of all the standard application web pages needed for the application. interface, described by Each page is represented as a text file Ehler (1991). This containing HTML coding, which func- application interface tioned as a template for the page shown was used for running on the Internet. On a given page cer- a database application tain locations were selected to contain BipsArch, which was the variable information from the developed by the greenhouse compartments. Any ob- project. BipsArch servation is given a specific name in the can connect to any standard database to distinguish it from climate computer any other observation. For instance, system through a the air temperature was assigned the well-defined, ven- identifier name TmpAir. The system dor-specific device then scans the database for the given driver, which re- combination of compartment number flects the structure and input name and retrieves the de- of the used climate sired record that contains all the data computer system. for the given observation, such as the BipsArch continu- observation value and the time and the ally updates a set of date, when the observation was per- Paradox databases formed. (Borland Interna- CYBGR4 parsed the text file and tional, 1992) with converted the values into standard- greenhouse infor- HTML code which can be shown by mation every 10 any browser. The new HTML file with min, effectively cre- the dynamic data was then written to ating a virtual green- the local disk. When all the new pages house. These had been generated, they were up- databases serve as a loaded to the university’s common Fig. 2. The main welcome screen of shared common and generic informa- web-server. To cater for special infor- the greenhouse web application. tion pool and standard interface for mation that was not part of the normal any greenhouse application that needs environmental computer system, specific information needs arising from, to access climate information or needs CYBGR4 also had the ability to gener- for instance, demands made by ongo- to update the set points of the ECC. ate new information by processing the ing experiments. BipsArch was developed using the typical environmental data, for example Borland Delphi 3.0 (Borland Interna- the maximum temperature of the last Materials and methods tional, 1997) programming language. 24-h period. This was calculated based SYSTEM OVERVIEW. The overall The greenhouse server also ran on the contents of the standard data- structure of the system, which was the web site generation software bases. The result was returned to the implemented at the greenhouse com- (CYBGR4) developed by the project. common database, thus supplying new plex of the Royal Agricultural Univer- CYBGR4 was responsible for generat- information which could be used by sity of Copenhagen is shown in Fig. 1. ing the necessary HTML-pages and other applications running on the Twenty greenhouse compartments uploading them to the university web- greenhouse server. were controlled by an environmental server, using a simple FTP protocol via control computer system (ECC) sup- an Ethernet connection. Results and discussion plied by the DGT-Volmatic A/S Cor- STRUCTURE AND FUNCTION OF STRUCTURE AND CONTENTS OF poration (Brøndby Strand, Denmark). THE WEB-APPLICATION GENERATOR THE WEB APPLICATION. The main struc- This system consists of seven PROGRAM CYBGR4. The main tasks ture consisted of a welcome screen LCC1200-microcomputers (DGT- of this program were to access the (<http://www.agsci.kvl.dk/ Volmatic, 1988) which function as necessary data from the greenhouse havebrug/realtime/indexe.htm>) climate registration and regulation standard databases and then integrate which was linked to a map of the total computers. They are connected to a these into HTML code for the web greenhouse operation. From the map, supervising PC—the greenhouse application. However, it was first nec- the user gained access to the data from server—in real-time using an RS232 essary to ensure that the standard data- any greenhouse compartment by click- interface. The software used were the bases contained the desired ing on the relevant part of the map. ● October–December 2001 11(4) 640 T&P 640 9/5/01, 12:01 PM The same data were shown for all com- partments, but new information could readily be added to a given page. All that was needed was to add the relevant BipArch code to the HTML template and if necessary add these data to the greenhouse standard database. This only called for one new line of code in the program. From the compartment page the user could either choose another compartment through the menu but- tons on left side of the screen, or return to the site map by clicking on the picture at the top of the menu. Performance and stability were considered as the highest priority. The web page generation system was located in an integral part of the greenhouse server. This could affect performance as the server needed to run efficiently so that all the other parts of the control systems for the greenhouses were not impaired in any way.