1、 The Design of Virtual Function waveform Generator Abstract In this paper, a Virtual Function Signal Generator is designed Based on Labview. How to design the generator is introduced in detail. The Virtual Function Signal Generator can generate basic wave such as Sine wave, formula wave, white noise
2、 etc. The generator has functions like wave showing and date saving in addition. Keywords- Virtual Instrument； Labview；Function Signal Generator I. INTRODUCTION The function signal generator is applied in great many of fields. Virtual Instrument is a new type of instrument which has especial functio
3、ns that old one do not have. One VI includes PC, hardware which is particularly designed and special software. Being a graphical programming language Labview is used for date gathering, instrument controlling and date analyzing. How to design virtual function signal generator by Labview is explained
4、 in detail in the following paper. II. TOTAL DESIGN According to the principle of function signal generator,four parts were designed to compose virtual function signal generator. These four parts are property setting, signal generating, wave showing and date saving. A. Panel of Generator In this sys
5、tem the panel are divided to property setting panel(fig.1) and total structure panel(fig.2) . Main options in the first one are frequency, amplitude, duty cycle and samples etc. about signal. These properties can be set in this panel. Total structure panel just includes four parts that were presente
6、d above and some additional parts. Figure 1.Property Set Panel Figure2.Total Structure Panel B. Function about Instruments The Virtual Function Signal Generator can generate basic waves such as Sine wave , special waves like formula wave and some kinds of noise. Signals frequency can be regulated de
7、licately or roughly. Property can be reset quickly and be used as subprogram sometimes. Moreover has the generator functions like wave showing and date saving etc. III. SOFTWARE ABOUT VIRTUAL FUNCTION SIGNAL GENERATOR The Virtual Function Signal Generator was designed base on Labview 7.0. There are
8、three modules which compose this system: module of property setting, wave generating, wave showing and saving. A. Module of Property Setting Frequency setting and property resetting are two important parts of this module. How to change frequency value multiply is explained in fig.3. Node Selectting
9、is applied repeatedly and skillfully so that data can be input in many channels. Then select data by switch button. So frequency controlling can be designed as real instrument. How to reset property quickly is explained in fig.4. Figure4. Property Reset Figure3. Frequency Control B. Module of Wave G
10、enerating This module is the core of the Virtual Function Signal Generator. Structure CASE is used in this work. By special node many types of waves can be generated. For example, how to generate sine wave is explained in fig.5. The other ones can be generated in similar way. Figure5.Graphical Progr
11、anm About Sine Wave Generate C. Module of Wave Showing and Saving In fact this module is a composite one which include many functions as operating, applying, debugging, showing etc. Because of lots of acts would be operated though this interface, this interface must be not only practical but also ni
12、ce. Fig.6 just explained how to solve these problems. Figure6.Graphical Program About Total IV. CONCLUSION Being graphical language, Labview is very strong and easy tool to make system of measure and test. Virtual Function Signal Generator based on Labview has advantages such as having friendly interface, operating easily etc. It can generate many types of function signals which have big range of value of frequency and its output datas can be saved. So it can be applied widely.
