Research And Application Of Remote Operation Techniques For Scientific Instruments

Scientific instruments as a tool for mankind to understand the physical world, are the basic conditions for scientific research and technological innovation. At present, the lack of overall scientific instruments resources is conspicuous contradiction in our country, and there are equipment deficiency, uneven distribution, low utilization, sharing problems…etc. For the present situation of the application of scientific instruments, building the remote sharing system for large-scale scientific instruments, can effectively, fully share the high quality resources of research equipments. The remote operation techniques for scientific instruments as the key technology of remote sharing system of instruments, has provided important technical support for implementation of the remote experiments and remote real-time control of large-scale instruments and related remote application services. Remote operation has become one of the important development trends of scientific instruments, which not only can overcome the geographical barriers to the use of instruments to improve instrument efficiency and save experiment costs, but also support real-time cooperations of remote instrument experiments from several scientists in different places to enhance scientific experiments level.Due to the variety of modern scientific instruments, complexity and discrepancy of system constitutes, large variety of operation methods, and diverseness for work platforms and software, extracting and resolving the common key technical issues involved in the process of building the remote operation system for scientific instruments will be helpful for instrumentation application developers to select feasible ways and means of a specific instruments, and develop the best technical solutions and means to quickly build a remote operation system platform. Construction of a remote operation system can make large number of instruments, which can only be operated locally, connected in network to expand its external communication capabilities and achieve remote access and control instruments and to facilitate the application and use of instruments and implementation of the remote experiments. Meanwhile, the instrument operation model and implementation technology involved in the construction of the remote system provide a reference for instrument manufacturers to design a remote measurement and control platform for the new generation scientific instruments.This paper concentrates on researching the scientific instruments remote operation techniques and system implementation, and solves a series of crucial technical problems in construction process of remote operation system for instruments covering: system model and implementation method, instruments network communications, remote access to operation software and control network security. It provides a remote operation model for scientific instruments based on communication data flow, discusses the implementation method and means. Based on this model, it chooses five different ways to acquire the control information, develops remote operation system implementation technology and application research from different communication levels.The main contents are as follows:(1) Research on remote operation model and implementation method for scientific instrumentsFor large number of existing scientific instruments, when it comes to how to efficiently and quickly achieve their remote operation, research work of system structure, implementation means and so on as common crucial technology is still relatively weak. A remote operation model of scientific instruments based on communication data flow is presented. Through the analysis of control signal path, we divides the path into eight main communication layers including: numerical operation systems, communications modules, instruments external communication, host operating system, internal I/O communication in software system, the professional instruments software, and HCI (Human–Computer Interaction) interface. In the eight communication layers, research work is carried out to propose the relevant implementation methods, which realize the remote operation of the instrument by intercepting that layer's data information and building networked terminal platform for remote operation. The eight types of methods have their own characteristics, their relevance and complexity varies from one to another, and they can not only be implemented alone, but also be used in combination with others. They provide a complete solution and technical reference for instrument remote operation system constructing.(2) Development and application of instrument network adapter based on embedded systemFor the situation that a large number of existing old scientific instruments do not have remote network communication capability and ensure the network security of instrument using, according to the communication modes and interface features of scientific instrument, the network adapter on the basis of embedded system is developed. The network adapter is used for transmitting instrument control information and data, and making instruments to get on the Internet. It safely separates instruments and network, which can make instruments avoid exposure in the network, and also the adapter filters all the data in the network, only transmitting the remote control information and data in specific format, and effectively resists various kinds of malicious attacks from the network, which guarantees the security of using instrument. To fit the instrument interface, work environment and other conditions, the adapter supplies various types of instruments interface, network communication modes and geographical positions, site images and other relevant information; and integrates multiple services of software and hardware, via flexible configuration, providing a comparatively comprehensive network access solution for instrument networking.(3) Research and implementation of remote operation system for scientific instruments based on data flow interceptingA remote control method based on data flow intercepting is proposed for scientific instruments with network communication interface. Develop data intercepting and transmitting software system for instruments external communication, in order to expand instruments remote communication capacity. Intercepted data from system transmission is the original instruments instruction data, which is in a small amount and has high real-time performance. This remote control method does not need any alteration of original instruments and software systems, and its implementation does not depend on the instruments platform. So its versatility is strong, and it is applicable to all kinds of scientific instruments with a network communication interface, and can also be extended to instruments with other communication interfaces. In addition, the system equipped with network server system, separates the control object from the controlled object to improve network security. Meanwhile, internal network can also be formed locally or remote end, to make several test instruments or remote computer systems share access to one public network IP address of Internet. In the remote system, only the server system has the fixed IP address, in this way IP address resources can be saved and address resources effectiveness can be enhanced. Using remote control method based on data flow intercepting for DSQ GC-MS, build a remote operation system efficiently and conveniently in the basis of original measurement and control platform of the instrument, and through the operation of the original instrument control software to achieve remote control of instruments.(4) Research and implementation of remote sharing system of scientific instruments under UNIX platformFor the graphical instrument measurement and operation software under UNIX platform, on the basis on X Window System, a software remote control method combined with virtual private network VPN technology and SSH remote login technique is proposed, which redirects input and output functions of measurement and control software, and designs and constructs the scientific instrument remote sharing system based on VPN. Instrument remote sharing system based on VPN is constructed by using the features of X Window System, and nothing is modified in the original software, so this method is also suitable for all kinds of remote operation for the measurement and control software of scientific instruments. The achievement of this method costs low, realizes easily and retains all the function of original system, and also it is meaningful for large-scale scientific instrument labs to develop and construct the instrument remote experiment system effectively. At the same time, three-layer VPN network framework constructed by this method will separate remote communication data of instrument from ordinary Internet network data safely, and ensure the safety of instrument system. This network construction can also be applied on remote sharing system achieved by other methods to protect the safety of network transmission, and it provides the reference for construction of safe and common instrument remote control network. There is a typical application on MAT900 mass spectrometer, through controlling remotely the host computer, remote access to the measurement and control software and the instrument is realized.(5) Research and implementation of remote operation system for scientific instruments based on API hookingFor instrument and control software in Windows, a remote control method based on API hooking is proposed. Development of I/O communications data interception synchronization software system, using API hooking to intrude the original control software, intercepts communication data flow between instrument and software, making the control program at remote end can communicate with instruments directly through the network, and in this way instrument software's long-distance communication capability is extended. Information transmitted in the system is the original instrument instruction data, in a small amount, and the system has high real-time performance. The remote operation method does not need any alteration of the original instruments and software systems, but its technology depends on the Windows operating system, which subjects to certain limitations. The remote system controls data flow in the software application layer, and no matter what method application program and the system use to localization objective function, the API hooking technology can guarantee that the interception is working. So in Windows, this method also has universality, and is applicable to various types of scientific instruments with external communication interface. For the LTQ mass spectrometer, using remote control method based on API hooking, develops a remote operation system efficiently and conveniently in the basis of original instruments measurement and control platform, and through the operation of the original instrument monitoring software to achieve instruments remote control.(6) Remote measurement and control software model for scientific instruments based on glue layerAccording to measurement and control software functions and tasks of property, using the method of modifying instrument control software, a remote measurement and control software model for scientific instruments based on glue layer is proposed. In terms of the work content of measurement and control software for scientific instruments, the model is divided into three-layer architecture: software and hardware interface layer, data acquisition layer and data processing layer. A glue layer, which was inserted into the data acquisition layer, divided the software into two parts. Adopting remote communication solution for glue layer, the networked control system was implemented. The remote measurement and control software model is applicable to remote sharing system transform for the existing scientific instruments in the case of having the source codes of instrument control software. At the same time, the model provides a reference for equipment manufacturers to design a new generation of scientific instruments for remote measurement and control platform: Uses the embedded system to realize the server which is built in the instruments, when the client software is integrated into the application software system, to achieve the remote operation for small and medium equipments; Or applies this model in the design of network measurement and control software for the large-scale scientific instruments. Applying the remote measurement and control software model for scientific instruments based on glue layer, it has developed the remote operation system for electron spectrometer and realized instrument's remote control and network experiment.