Computer is the backbone of the measurement and control system.
The application of computerized instrument technology such as bus instrument and virtual instrument makes it easier to establish centralized and distributed measurement and control systems. However, centralized measurement and control can not meet the needs of complex, remote and large-scale measurement and control tasks, so it is very necessary to set up a networked measurement and control system, and the continuous upgrading and progress of computer software and hardware technology provides more and more superior technical conditions for setting up a measurement and control network. Unix, WindowsNT, Windows2000, Netware and other networked computer operating systems bring convenience to the establishment of networked test system. Standard computer network protocols, such as OSI open system interconnection RM and TCP/IP protocol used on the Internet, have great advantages in openness, stability and reliability, and it is easy to realize the architecture of measurement and control network by using them. In developing software, such as Labview and LabWindows/CVI of NI company, VEE of HP company, VB and VC of Microsoft company, there are toolkits for developing network application projects. Software is the key to the development of virtual instrument, and Labview and LabWindows/CVI are very powerful, which not only makes the development of virtual instrument simple and convenient, but also provides reliable and convenient technical support for making virtual instrument online. TCP class library is encapsulated in LabWindows/CVI, which can develop network applications based on TCP/Ip. The TCP/IP and UDP network VI of Labview can establish communication with remote applications, and its Internet toolbox also adds e-mail, FTP and Web functions to the application system. With remote automation VI, you can also control the distributed VI that controls other devices. In LabVIEW 5. 1, there is also a special network function, which improves the ability to develop network applications.
The computer, high-end peripherals, communication lines and other hardware resources, as well as large-scale databases, programs, data, files and other software resources into the network, can realize the * * * enjoyment of resources. Secondly, by establishing a networked measurement and control system to increase the redundancy of the system, the reliability of the system can be improved and it is convenient for the expansion and change of the system. The network with computers and workstations as nodes is equivalent to the network of modern instruments. Computer has become the pillar of modern measurement and control system.
Network technology is increasingly becoming the key support for measurement and control technology to meet the actual needs.
Nowadays, the rapid development of computer networks represented by the Internet and the improvement of related technologies have broken through the time and space limitations and geographical barriers of traditional communication methods, making it very easy to communicate in a wider range. The software and hardware resources owned by the Internet are being applied in more and more fields, such as e-commerce, online teaching, telemedicine, remote data acquisition and control, remote real-time call of high-grade measuring instruments and equipment resources, remote equipment fault diagnosis and so on. At the same time, the continuous progress of high-performance, high-reliability and low-cost network interconnection devices such as gateways, routers, repeaters and network interface chips has facilitated the interconnection between the Internet, different types of measurement and control networks and enterprise networks. Using the existing internet resources, it is very convenient to set up a measurement and control network, an enterprise intranet and its interconnection with the Internet without establishing a special topological network, paving the way for the universal establishment and wide application of the measurement and control network. As an embedded application, TCP/IP protocol is embedded in the ROM of field intelligent instruments (mainly sensors) to receive and send signals in TCP/IP mode. In this way, the measurement and control system relies on the intranet in data acquisition, information release, system integration and so on, and connects the measurement and control network with the intranet and the Internet, which is convenient to realize the unification of the measurement and control network and the information network. In such a measurement and control network, traditional instruments and equipment play the role of independent nodes in the network, and information can be transmitted to any field across the network, so real-time, dynamic (including remote) online measurement and control becomes a reality. Compared with the past measurement and control technology, we can easily find that today's measurement and control can save a lot of on-site wiring and expand the geographical scope of the measurement and control system. The expansion and maintenance of the system is extremely convenient because the network plays an irreplaceable key role in the execution and completion of this modern measurement task, that is, the network really intervenes in the whole process of modern measurement and measurement and control. Intranet is an information network based on Web, and it is the mainstream of enterprise internal information network at present. The application of Internet open interconnection communication standard makes Intranet an open system based on TCP/IP protocol, which can easily connect with the outside world, especially the Internet. With the help of Internet related technologies, Intranet can bring great convenience to the operation and management of enterprises, and has been widely used in all walks of life. The Internet has also begun to exert more and more influence on the traditional measurement and control system. At present, the design idea of measurement and control system is obviously influenced by computer network technology. Based on the principles of networking, modularization and openness, the measurement and control network has changed from the traditional centralized mode to the distributed mode, and moved towards openness, interoperability, decentralization and networking. Intelligent measurement and control system. There are not only computers and workstations, but also intelligent measurement and control instruments on the nodes of the network. The measurement and control network will have an architecture and communication model similar to the information network. For example, the communication model of fieldbus, which is developing rapidly in the current measurement and control system, corresponds to the OSI model. On-site intelligent instruments and equipment are used as nodes, and the nodes are connected with the instruments and equipment in the control room through the network to form an organic measurement and control system. The function of the measurement and control network will be far greater than the sum of the functions of each individual in the system. Therefore, the function of the measurement and control system is significantly enhanced, and the application field and scope are obviously expanded. Jini software technology comes out. Jini software technology aims to connect all kinds of electrical equipment, measuring instruments and devices using JAVA chips to the Internet. Jini software and simple programs written in Java language can make any networked instrument and equipment realize its own functions and be used by other instruments and equipment at the same time.
The emergence of network technology is and will greatly change all aspects of people's lives. Specifically, in the field of measurement and testing, measurement and control technology and instruments, networking of computerized instruments, regional, national and even global resource sharing of high-end measurement instruments and equipment, cross-regional implementation of direct digital traceability comparison of various measurement standards, remote data acquisition and measurement and control, remote equipment fault diagnosis, automatic meter reading of electricity, water, gas and heat energy, etc. It is the inevitable result of the progress of network technology and its comprehensive intervention.