The development of accurate computer control of a 3 MV Van de Graaff accelerator operation is described. The developed system comprises the accelerator turn-on and turn-off procedures during a normal run, which includes the setting of the terminal voltage, ion source light up, beam focusing and control of ion beam current and energy during operation. In addition, the computer monitors the vacuum and is able to make a detail register of the most important events during a normal run. The computer control system uses a LabVIEW application for interaction with the operator and an I/O board that interfaces the computer and the accelerator system. For everyday operating conditions the control implemented is able to turn-on and off the machine in about the same time as a specialized technician. In addition, today more users can make experiments in the accelerator without the help of a specialized operator, which in turns increases the number of hours during which the accelerator can be used.
Electronic voltage transformers (EVT) and electronic current transformers (ECT) are important instruments in a digital substation. For simple, rapid and convenient development, the paper proposed an on-site calibration system for electronic instrument transformers based on LabVIEW. In the system, analog signal sampling precision and dynamic range are guaranteed by the Agilent 3458A digital multimeter, and data synchronization is also achieved based on a self-developed PCI synchronization card. To improve the measurement accuracy, an error correction algorithm based on the Hanning window interpolation FFT has good suppression of frequency fluctuation and inter-harmonics interference. The human-computer interface and analysis algorithm are designed based on LabVIEW, and the adaptive communication technology is designed based on IEC61850 9-1/2. The calibration system can take into account pairs of digital output and analog output of the electronic voltage/current transformer calibration. The results of system tests show that the calibration system can meet the requirements of 0.2 class calibration accuracy, and the actual type test and on-site calibration also show that the system is easy to operate with convenience and satisfactory stability.
In this paper the design and implementation of a plug-and-play analog resistance temperature sensor is presented. The smart temperature sensor consists of an analog sensor element with transducer electronic data sheet (TEDS) memory device and a network- capable application processor (NCAP) connected through a mixedmode interface (MMI). The mixed-mode interface and NCAP front-end electronic support have been implemented by the use of a standard 8-bit microcontroller. NCAP's application processing and network communication functions are implemented based on the concept of virtual instrumentation using a PC. The implemented NCAP can also be used as a plug-and-play stand-alone data acquisition system or as development system for plug-and-play sensors compliant with the IEEE 1451.4 standard. Details of sensor implementation and test results are included in the paper.
As a consequence of recent implementations of EU Directives related to noise protection more and more students of various AGH-UST programs are introduced to the basics of acoustic measurements. Students at various levels of theoretical background in the field of acoustic measurements are offered practical training in measurements using digital sound analyzers. The situation would be optimal if each student could have a device at his/her own disposal. Unfortunately, such a situation is not possible at the moment because of various reasons. With the above problem in mind, a dedicated software package has been developed, implemented in the LabVIEW environment, which allows detailed studies of problems related to the acoustic signal measurement using sound level meters, as well as tasks in spectral analysis (1/1 and 1/3 band filters) and narrow-band (FFT) analysis. With such organization during the introductory laboratory classes each student is offered a direct individual contact with a virtual device that is properly pre-programmed for realization of a well-constructed learning process. It definitely facilitates understanding of the essence of acoustic signal measurements and provides a good basis for further laboratory work carried out as a team-activity.