In the world of Test and Measurement, Signal Sources are viewed as one of the major categories of instruments which produce reference signals for other devices. There is a great variety of signal types, such as digital, analog, modulation, noise, pulse, and so on. Each signal type has specific characteristics such as time, frequency or amplitude.

The most fundamental signal is the sine wave. However, in many cases, other signals are needed for different applications: square waves for digital systems, modulation signals and noise for communication systems, pulse signals for radar, or arbitrary waveforms for special applications. A typical signal generator, known as a function generator, creates sine, square and triangle waves.

Integrated Services provides a wide range of signal source products, including arbitrary function generators, function generators, AM/FM signal generators, audio generators and radio frequency generators. There are two categories of function generators - DDS (Direct Digital Synthesized) and conventional (Analog) types.