Zdalny dostęp do laboratorium wielkości nieelektrycznych

W artykule przedstawiono system pomiarowy do wyznaczania, na odległość za pośrednictwem Internetu, charakterystyk czujników temperatury w Laboratorium Miernictwa Wielkości Nieelektrycznych. System zawiera: komputer, termostat cieczowy wraz z umieszczonymi w nim czujnikami temperatury, termostat o stałej temperaturze, multimetr Agilent 34970A z 16-kanałowym multiplekserem 34902A oraz kartę interfejsową USB/ GPIB służącą do połączenia przyrządu z komputerem. Komputer jest wyposażony w kartę sieciową z przydzielonym numerem IP.

A measuring system for remotely determining, by means of the Internet, the characteristic of temperature sensors in the Laboratory of the Nonelectrical Quantities Measurements is described. The system includes: a thermostat with adjustable temperature, a thermostat with a constant temperature, measuring instrument Agilent 34970A with a 16-channel multiplexer 34902A, a USB/GPIB interface card, which connects the instrument and a local computer (Fig. 1). The computer is equipped with a network card with an assigned IP address. The system was con-structed according to the client-server architecture (Fig. 2). The software for the system was written in LabVIEW 7.0 programming environment. Client communication with a server takes place by means of the DataSocket technology, which uses the TCP/IP protocol. The configuration of the DataSocket is shown in Fig. 3. A client program is used to communicate with the server and to create a user interface. The main panel of the client application for tem-perature sensor measurements is shown in Figs. 4 and 5. A server program is used to communicate with the client and to service the measuring instrument. The Main Panel of the server application shows the actual measured results and instrument state (Fig. 6). To create the servicing program the Instrument I/O Assistant of the LabVIEW program was used (Fig. 7). The realized measuring system will be used during the Sensor Fundamentals and Nonelectrical Quantities Measurements lectures.