Abstract : Parameter testing of DC speed control devices is a fundamental measure to ensure product quality and reduce failure rates. Existing testing methods and techniques cannot meet the automation requirements of enterprises. Based on the development of testing technology and the actual requirements of manufacturing enterprises, this paper utilizes a self-developed novel multi-parameter hardware testing system for DC speed control devices and develops a testing software platform based on LabVIEW technology. The design and development process of this software platform is described in detail. Practical use shows that the software platform has excellent stability and maintainability, and high testing accuracy. Keywords : DC speed adjusting device; parameter testing; software platform; LabVIEW CLC Number: Document Code: A Design and Realization of the Parameter Test Software Platform of DC Speed ​​Adjusting Device [align=center]Li Hong-wei1,2,Ding Ru1,Zheng Tong1 (1. Automation Engineering Department, Tianjin University of Technology and Education, Tianjin 300222, China; State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, China) Abstract: The parameter test of DC speed adjusting device is the prime method for ensuring product quality and reducing breakdown ratio. Some existing test means and methods cannot satisfy the need that corporations develop toward autoimmunization. According to the actual needs of corporations and the development of test technology, test... This paper develops a software framework based on LabVIEW technology based on the new parameter test system of DC speed adjusting device. The design and development process are introduced in detail. The actual application shows that it is reliable, easy to maintain and can achieve high accuracy. Keywords: DC speed adjusting device; Parameter test; Software platform; LabVIEW 1. Introduction DC speed adjusting device has a wide range of applications in the field of automation control. Many control systems use Siemens 6RA70 series DC speed adjusting device as the core control equipment[1], which has an important impact on the entire system. Strict product testing is the fundamental measure to ensure its quality and reduce the failure rate[2]. At present, the testing of DC speed adjusting device parameters at home and abroad mainly adopts manual and semi-automatic methods. These methods require specialized test personnel. The measurement of each parameter requires manual setting of relevant data and recording of test results. The amount of data to be recorded is large, which is easily affected by human factors and external interference. Moreover, the operation is cumbersome and complicated, which cannot meet the requirements of modern production enterprises for production efficiency, product quality testing, system updates and other aspects. Based on the development of DC speed control device parameter testing technology at home and abroad and the actual requirements of manufacturing enterprises, this paper takes the 6RA70 series DC speed control device as the basic object[3] and designs a new type of DC speed control device multi-parameter testing system. Based on this hardware system, a multi-parameter testing software platform for DC speed control devices based on LabVIEW technology is developed. This software platform can also perform parameter testing on other series of DC speed control devices. 2. Test system structure The structure of the DC speed control device multi-parameter testing system is shown in Figure 1. It consists of six parts: computer system, power supply system, instrument unit, PLC control unit, load unit and self-test unit. The power supply system provides the various voltages required by the DC speed controller and the load motor; the instrumentation unit includes digital multimeters, oscilloscopes, etc.; the computer system communicates with the DC speed controller (x300 bus, Modbus protocol), and with various instruments and PLC units. It issues corresponding test commands to the test system, acquires various operating parameters of the DC speed controller in different test environments in real time, analyzes and processes the test data, and displays the test results; the load unit loads the tested object to meet the operating requirements of the DC speed controller under rated load, and acquires parameter information of the tested object under load; the self-test unit consists of encoders, analog tachometers, etc., including the detection of system initialization information and the acquisition of operating status data of each actuator in the load unit, which is fed back to the DC speed controller in real time to achieve parameter comparison and ensure the normal operation of the system. [align=center] Figure 1 Test System Block Diagram[/align] 3. Software Platform LabVIEW, as one of the industry standards in the field of testing and measurement, can be used to construct a practical data acquisition system through GPIB, VXI, PLC, serial devices, and plug-in data acquisition boards. It provides the largest instrument driver library in the industry and supports data sharing through interactive communication methods such as Internet, ActiveX, DDE, and SQL. In addition, due to LabVIEW's powerful hardware driver, graphics display capabilities, and convenient and fast programming, it provides excellent solutions for process control and industrial automation applications [4-5]. Given the advantages of LabVIEW technology, this software platform was developed in the LabVIEW 7.0 Express environment, relying on LabVIEW's fully functional software development environment and its powerful programming language to realize the various functional requirements of the system [6]. According to the actual testing requirements, this software system mainly supports the following requirements: plug-in device type (oscilloscope, multimeter), bus type device, parallel port and serial port device type (printer, scanner), database, permission management, and user interface. Therefore, the design scheme divides the system into 5 major modules, namely the main program, hardware driver, database management program, permission management program, and interface display and human-computer interaction program. Figure 2 is a schematic diagram of the software platform architecture. 3.1 Main Program The main program is the only interface for users to access the software, and it is also the core connecting the various program modules and the main line of data flow. At the beginning of program execution, the main program initializes various data variables and parameter flags. Computer time is read from the system by a separate thread and passed to other interfaces via global variables. This thread is also responsible for the termination and exit of the entire software. Its code is shown in Figure 3. The main program is responsible for collecting and distributing data from each subroutine; therefore, a reasonable and efficient data transfer method is a crucial task for the main program. Based on requirements such as data acquisition volume, acquisition frequency, real-time performance, and importance, the main program selects technologies such as Notification and queue from the Synchronization template to ensure data synchronization and optimal use of system resources. To further save system resources and improve software stability, considering the relatively low usage frequency of each sub-interface, LabVIEW's dynamic calling technology is used to operate each sub-interface; that is, it is only loaded into memory and run when the user clicks a button on the main interface. 3.2 Hardware Driver The hardware driver mainly consists of two parts: direct LabVIEW drivers and third-party driver libraries. The block diagram of the hardware driver is shown in Figure 4. The driven hardware is roughly divided into two categories: direct LabVIEW drivers and third-party hardware drivers. Hardware directly driven by LabVIEW includes Windows default printers and hardware that can be detected by MAX; third-party hardware drivers are devices that MAX cannot directly recognize. [align=center]Figure 4 Hardware Driver Block Diagram[/align] 3.3 Database Management Program The standard version of LabVIEW does not include function nodes for database operations. Given that the additional function packages provided by NI are relatively expensive, this software system uses self-made functions to manage and read/write the database. The self-made functions are based on Microsoft ADO technology and SQL language. According to the common ODBC method, the Microsoft ActiveX Data Objects (ADO) data access technology provided by Microsoft is used to establish and access the database, realizing the daily data addition, deletion, modification, query and other functions. The database operation flow is shown in Figure 5. [align=center]Figure 5 Database Operation Flow[/align] 3.4 Permission Management Program Permissions adopt a two-level management method, divided into super users and ordinary users; super users have full permissions and can delete historical information, while ordinary users only have browsing permissions; user passwords can be stored in the database, registry or file. The superusername is fixed, while the password can be modified; multiple ordinary users can be added arbitrarily. When a user attempts to log in to the system, the program will verify their validity. If the verification passes, based on their user permissions, the corresponding menus, buttons, and panel controls will be disabled according to their permission set. 3.5 Interface Display and Human-Computer Interaction The program interface display will fully utilize LabVIEW's various display controls and reasonable layout to achieve both an aesthetically pleasing user interface and good human-computer interaction functionality. Data and graphics display are required in the main interface and other interfaces. Data display is relatively simple. The processed data is passed to the thread responsible for interface display through a queue, and the thread determines whether the data is out of tolerance and what color to use to display the numbers based on user needs. For curve graphics display, a blank template needs to be created first, containing all fixed text content and positions. Based on the input data, the tolerance zone and other markings are drawn on the template, and the influence of the slider is added so that the tolerance zone can change according to the slider control. Then, an endpoint array is added to connect them into a closed curve, and finally, the display data is entered for output. 4. Practical Application In order to test the effectiveness of the software platform, this paper combines the designed multi-parameter hardware test system and software platform of DC speed control device to conduct actual testing on various parameters of Siemens 6RA70 series device. The main interface is shown in Figure 6. Through actual use, it is proven that the software runs normally, has a short response time, complete functions, is easy to maintain, and has high test accuracy. [align=center] Figure 6 Test running interface[/align] 5. Summary This paper introduces the design and development process of the DC speed control device parameter test software platform based on LabVIEW technology. Practical use proves that the design idea is correct and the scheme is feasible. It provides a new and effective software platform for the efficient and accurate automatic testing of DC speed control device parameters and has certain reference value for the development of similar application systems. References [1] Yang Xuefeng. Development of simulation debugging software for Siemens 6RA70 series controller. [Master's Thesis], Shandong: Shandong University, 2001 [2] Li Yunfei, Tan Zhenfeng, et al. Design and implementation of general test software platform for frequency converter [J]. Computer Engineering and Applications. 2007, 47(10): 115-116 [3] SIMOREG DC Master 6RA70 series instruction manual. Siemens Electrical Drives Ltd. http://www4.siemens. [4] Xue Chaogai, Cao Haiwang, Gu Wentao. Development of dynamic parameter testing system based on virtual instrument [J]. Microcomputer Information. 2006, 22(7): 96-98 [5] Guan Hao, Sun Rutong, Liu Ansheng. Application of virtual instrument technology in hydraulic system testing [J]. Machine Tool & Hydraulics. 2003, 3: 301-302 [6] Yang Leping, Li Haitao, Yang Lei. LabVIEW Programming and Application (Second Edition) [M]. Beijing: Electronic Industry Press, 2007. About the author: Li Hongwei (1978-) male, from Tianjin, lecturer, master's student, major research direction: modern sensing and testing information technology, intelligent instruments. Telephone: 13920677713, Email: [email protected] Ding Ru: (1977-) Female, from Nong'an County, Jilin Province, Lecturer, Master's degree, Main research direction: Measurement and control technology and instruments Zheng Tong: (1970-) Male, from Tianjin, Associate Professor, Master's degree, Main research direction: Modern sensing and testing information technology, intelligent instruments.