The Absolute Value block is a control generator that takes an audio signal and outputs its absolute value as a control signal — a full-wave rectifier that follows the instantaneous magnitude of the waveform. It has one audio input and one control output, with no audio output; in stereo it averages the absolute values of the two channels. There are no adjustable parameters.
On every tick it reads the current audio sample (or the mean of the two channels in stereo), takes its absolute value, and writes that to the control output, where it can drive any control-domain parameter. It processes one sample-frame per tick, in step with WaveWarp's sample-per-sample engine.