This section provides a closer look at the signal generators that performed best during the market research and seemed most important.
The Visual Analyzer shown in figure 1 by A. Accattatis is a full-featured signal measurement and generator software which uses a standard PC soundcard as signal processing hardware.
The waveform generator forms just a small part of the application. It supports all standard waveforms, pulses, noise, and arbitrary waveforms through modulation or by loading an existing waveform from a file. The user-interface of the Visual Analyzer consists mainly of basic operating system native controls. Therefore, and because of the high amount of features and functions embedded into the user-interface, the target group of the application are rather more advanced and professional users. The OpenLab Signal Generator, in comparison to the Visual Analyzer, tries to simplify the GUI (Graphical User Interface) in order to enable easy access to hobbyists and beginner students. In addition, the OpenLab Signal Generator uses external hardware to increase the maximum output voltage and enable offset generation.
Figure 2 shows a screenshot of the software signal generator solution from C.Zeitnitz. The program also features an oscilloscope and a spectrum analyzer which are not depicted here. It uses the LabView Runtime, hence its familiar look and feel. The channels are clearly separated and can be controlled by knobs or text input. Apart from the standard waveforms, it also supports generating signals through a formula. Channel 2 shows this configuration.
Although the signal generator has no preview window, the signal can be looped back internally and seen in the oscilloscope window. As a whole, using the signal generator was perceived quite intuitive and straightforward. For private and non-commercial use the application is free, otherwise a license is required which costs about 10e per installation excl. VAT. Additional hardware is not available.
The content of his chapter is taken from the master thesis "Development of a Sound Card Based Arbitrary Waveform Generator" by Jakob Kriegbaum, MSc, May 2017.
Alfredo Accattatis: Visual Analyser Project [Online] http://www.sillanumsoft.org/hardware.htm
Christian Zeitnitz: Soundkarten Oszillograph [Online] www.zeitnitz.eu/scope_de
Bernd Reisner: AF Signal Funktions Generator [Online] http://www.dsp4swls.de/sigen/signalgen.html
Daqarta: Daqarta Data AcQuistion and Real-Time Analysis [Online] http://www.daqarta.com/dw_gen.htm