What makes an arbitrary waveform generator arbitrary

function generatorgeneratorsignalwaveform

Why are some signal or waveform generators called "Arbitrary Waveform Generators"? Am I misunderstanding the word arbitrary? This question is not necessarily about the word arbitrary but more about arbitrary signals.

How is a arbitrary waveform generator different from a plain old waveform generator?

Best Answer

An AWG is more like a soundcard on steroids, while your POWG contains circuitry for generation of a classical set of waveforms.

The lines are a tiny bit blurry since there are DDS waveform generators that only do a standard configurable set.

Basically for the classical waveform generators and the clunky pushbottons for waveforms (square, sawtooth, sine etc.) you activated a distinct circuit that was responsible for the type of waveform.

In the modern ones, you use DDS (direct digital synthesizers) that are highspeed DACs disciplined by an accurate reference clock. Since they are more or less fed with a waveform (lots of them can take .wav or even .mp3 files and play them back at desired frequencies) the waveforms they can produce are called arbitrary.