Abstract:

A typical system of Virtual Instrumentation (VI) is constituted by a set of devices capable of communicating between them and for a program that controls the mentioned communication. The device that controls the system of virtual instrumentation is a computer, whereas other devices are measurement devices (multimeters, oscilloscopes, sensors…) and other equipments (generators of sign, power sources, speed controls of motors…).
From the information loaded by the different devices we can change the conditions of the test, modifying parameters of the measurement instruments.

In an environment as the described one, the current trend is that a specialized software controls the system, coordinating the functioning of the different elements. One of these programs software is LabView of National Instruments ™. Labview allows to load, to analyze and to monitor the information inside a graphical programming environment in which there are assembled objects called virtual instruments to form the program of application with which the user will interact.

In addition LabView allows the information representation in interactive panels that work as if it was a real instrumentation, and it allows multiple options of information treatment, as his storage on disc and to share them in network or with other applications. The interaction with other applications will be able to be carried out by means of calls to bookshops of dynamic link (DLL: Dinamic Link Library) and dynamic exchange of information (DDE: Dynamic Data Exchange) in local way or by means of TCP/IP in remote connections. Always looking for independence of the platform in which we have carried out our application.
A measurement instrument that we can have in any laboratory remains perfectly defined by a few controls and a few elements of representation. However, a virtual instrument will be related to the concept of software. This software will execute in a computer that will have a few elements lodged hardware concrete, information acquisition cards (analogical and digital), cards of interface with the buses of instrumentation and a few channels of control also analogical and digital.

Our virtual instrumentation will allow to operating with this hardware by means of a user's graphical interface that will be the controls panel of the habitual devices (Oscilloscope, multimeter, etc.). By means of its representation on screen of the graphical elements of visualization and control that will use as interface with the user, this one will observe the conditions of the income selected in the screen and will interact directly or by means of the execution of the routines that finds programmed.
In this forma, the student of engineering will be able to help and to prove a virtual simple instrument in order to familiarize itself with LabVIEW's managing and will be able to penetrate into the knowledge of the electronics from a theoretical and experimental point of view, being able to compare both results in situ.

Keywords:

Virtual instrumentation, Labview application, Electronic.