Abstract: To achieve network-based collaborative monitoring of the greenhouse environment, a networked greenhouse monitoring and control system based on Datasocket was designed on the LabVIEW 7.1 virtual instrument development platform, organically combining virtual instrument technology and network technology. This paper details the hardware and software components of the system and the implementation method of remote monitoring. Keywords: Virtual instrument technology; LabVIEW; Greenhouse; Remote measurement and control [b][align=center]Designing Network Greenhouse Measurement and Control System with Virtual Instrument Wang Wendi Tang Juan Lv Changfei Huo Xiaojing[/align][/b] Abstract In order to realize network interoperable monitoring of the greenhouse environment, a set of greenhouse remote measurement and control system is designed based on Datasocket in virtual instrument development platform—LabVIEW 7.1, combining network technology with virtual instrument technology. The systemic hardware composition and systemic software are introduced, and at the same time, a way of realizing network monitoring is provided. Keywords Virtual instrument technology; LabVIEW; Greenhouse; Remote measurement and control CLC number: TP39 Document code: A 1 Introduction With the continuous improvement of computer technology, modern measurement and control systems are developing towards automation, intelligence, miniaturization, and networking of instruments. The emergence of Virtual Instrument (VI) has brought about a revolution in modern measurement and control technology. It utilizes the powerful functions of computer systems combined with corresponding software to greatly break through the limitations of traditional instruments in data processing, display, transmission, and storage. The integration of virtual instrument technology and network technology has enabled virtual instrument systems to break through the traditional measurement concept, enabling measurement data to be shared in a true sense and enabling remote measurement to be realized. Traditional greenhouse monitoring and control systems are often operated on-site, and greenhouse monitoring is limited by geographical location. Therefore, we have designed a networked greenhouse monitoring and control system using virtual instrument technology, so that remote clients can monitor and control the greenhouse through a local area network or the Internet, thus realizing a true virtual instrument. 2 Networked Virtual Instrument Technology Networked virtual instruments are also called virtual instrument networking[1]. Its general characteristics refer to the inclusion of virtual instruments, expensive external equipment, test points and databases into the network to achieve resource sharing and jointly complete the test task. Using networked virtual instruments, people can obtain measurement information or data at any location and at any time. Networked virtual instruments are also suitable for remote or remote monitoring, data acquisition, fault detection, alarms, etc. Networked virtual instruments separate the three main functions of traditional instruments—data acquisition, data analysis, and graphical display—which are typically handled by a single computer. These functions are implemented using independent hardware modules connected via network cables. The network's capabilities far exceed the individual functions of each component. Various types of networked virtual instruments can be constructed based on specific engineering needs. A networked virtual instrument consists of the following components: a network operating system, a virtual instrument (with network testing capabilities), distributed I/O system modules, a data acquisition card, and a controller. Currently, common virtual instrument platforms typically have many network-related functions, making the creation of networked virtual instruments easier and more convenient, without requiring the learning of complex TCP/IP transmission protocols. As testing systems become increasingly large and test nodes or PCs are widely distributed, distributed I/O system modules are needed. These modules provide three types of components: I/O modules, junction boxes, and network modules, offering the most economical solution for industrial testing and control applications. Users can integrate these modules into existing virtual instrument systems via Ethernet or communicate with serial devices such as RS-232 and RS-485. The data acquisition card (DAQ) used in network testing must have driver software for remote data device access (RDA) to enable resource sharing on the network. The instruments used in network testing must be controllers with network functionality, i.e., GPIB-ENET. 3 System Composition 3.1 System Hardware Configuration The networked greenhouse monitoring and control system hardware consists of temperature sensors, humidity sensors, light sensors, data acquisition boards, hubs, Datasocket servers, and remote computers, as shown in Figure 1. The temperature sensor is a JWSL temperature transmitter, the humidity sensor is a JWSL humidity transmitter, the light sensor is a ZD-VB illuminance transmitter manufactured by Beijing Kunlun Coast Sensor Technology Center, and the data acquisition board is the PCI6024E plug-in data acquisition board manufactured by NI (National Instruments). [align=center]Figure 1 System Hardware Structure Diagram[/align] This system uses temperature, humidity, and light sensors to collect real-time data from the greenhouse and transmit it to the PCI6024E data acquisition board. The board converts the collected electrical signals into digital signals that a computer can recognize, which are then processed by a pre-programmed real-time data analysis program. This enables data acquisition, display, real-time transmission, and analysis. Simultaneously, using an Ethernet interface, the system connects to other analysis systems or networks via communication and data publishing modules. 3.2 System Software Design The introduction and implementation of virtual instruments brought about a revolution in measurement and control technology, and people began to accept this new instrument concept. LabVIEW, as a timely and excellent measurement and control software development platform and virtual instrument building environment, has been widely promoted and applied. LabVIEW (Laboratory Virtual Instrument Engineering Workbench) is a development environment based on the graphical programming language G, developed by National Instruments (NI). It combines a simple and easy-to-use graphical development environment with a flexible and powerful programming language, providing an intuitive environment that is closely integrated with measurement hardware, allowing users to quickly develop various virtual instrument systems that meet their needs. Using LabVIEW for principle research, design, testing and implementation of instrument systems can shorten the system development time and greatly improve production efficiency [2]. Therefore, the application software of this system is developed and implemented based on the LabVIEW platform. The system software structure is shown in Figure 2. [align=center] Figure 2 System software module composition[/align] All software modules of the system are developed in the LabVIEW 7.1 environment. The networked greenhouse monitoring and control system using virtual instrument technology consists of the following modules: (1) parameter setting module; (2) data acquisition module; (3) data processing module; (4) remote control module; (5) system help module. Each module is independent of the others. This is very useful for software design and future upgrades and improvements, ensuring the independence of each module development. The parameter setting module is responsible for setting parameters such as the parameters to be measured, acquisition channel number, sampling interval, alarms, and control equipment within the greenhouse. The data acquisition module is responsible for collecting temperature, humidity, and light signals. The data processing module is responsible for digital filtering, abnormal signal removal, and numerical conversion of the measured signals. The remote control module enables remote clients to monitor and control the greenhouse. The system help module provides operators with information on system functions and operation. 3.3 Networked Measurement and Control LabVIEW's powerful network communication capabilities allow users to easily achieve remote measurement and control. This system uses DataSocket technology for remote measurement and control. DataSocket is a programming tool provided by NI that allows data transfer between different applications and data sources. DataSocket can access local files as well as data on HTTP and FTP servers. DataSocket provides a consistent API (Application Programming Interface) for low-level communication protocols, eliminating the need for programmers to write specific program code for different data formats and communication protocols. Moreover, these data sources can be distributed across different computers. DataSocket uses an enhanced data type to exchange instrument-type data, which includes data characteristics (such as sampling rate, operator name, time, and sampling accuracy) and actual test data. DataSocket uses a URL similar to a Uniform Resource Locator (URL) in the Web to locate data sources. Different prefixes in the URL indicate different data types: file indicates a local file, http is Hypertext Transfer Protocol, ftp is File Transfer Protocol, OPC (OLE for Process Control) indicates that the accessed resource is an OPC server, and dstp (DataSocket Transfer Protocol) indicates that the data comes from a DataSocket server's real-time data [3,4]. The server-side and client-side software are written using DataSocket technology. The specific steps are as follows: First, set the DataSocket connection properties of each control on the server's front panel and write the server program; then, copy all controls from the server-side front panel to a new VI, so that the client-side front panel is exactly the same as the server-side front panel; since DataSocket can only transmit control data (the value of the control's corresponding variable) and not control properties, the client program is written based on the characteristic that changes in control properties are caused by changes in control values. This allows the client and server-side front panels to operate in identical ways. The client can not only display the real-time data and control status of the greenhouse shown on the server-side front panel, but also control the actions of the controls on the server-side panel, thereby achieving the purpose of networked monitoring and control of the greenhouse. 4. Conclusion Introducing network technology into the field of measurement and control is not only an inevitable trend in the development of virtual instruments but also a requirement for many measurement and control tasks. Through networked virtual instruments, people can not only share measurement data but also build networked measurement and control systems, thereby improving measurement and control efficiency on a larger scale. Practice has proven that the networked greenhouse remote measurement and control system developed using LabVIEW 7.1 fully utilizes virtual instruments and networks to maximize the advantages of existing software and hardware resources and networks, achieving the most efficient and rational allocation of various resources, adapting to the needs of networking, and possessing broad application prospects. The author's innovation lies in building a networked greenhouse measurement and control system based on DataSocket technology using networked virtual instruments to achieve remote monitoring of greenhouses. References: [1] Wang Cheng, He Zhiwei. Interconnection and implementation of automated testing system based on networked virtual instrument [J]. Computer Measurement & Control, 2002, 10(2): 84-86 [2] Deng Yan, Wang Lei et al., eds. LABVI EW7.1 Test Technology and Instrument Application [M]. Beijing: Machinery Industry Press, 2004 [3] Wang Zhipeng, Wang Xin, Xu Zhenliang. Research and application of DataSocket technology in remote testing [J]. Microcomputer Information, 2006, 5-1: 136-138 [4] Ma Hairui, Zhou Aijun. LabVIEW remote measurement and control based on DataSocket technology [J]. Modern Instrument, 2005, (4): 20-23