The trigger setting of an oscilloscope determines the time at which the oscilloscope starts to acquire the signal. The basic concept behind the oscilloscope trigger function is that some of the incoming signal is fed into a comparator circuit. When the voltage of the waveform reaches a previously defined trigger condition (e.g. it crosses a threshold level), the data acquisition is initiated. The oscilloscope trigger function also enables repetitive signals to be displayed on the screen as a fixed waveform such as a sine wave. With a digital trigger this is done behind the A/D converter on the already digitized data. This results in a very low trigger jitter and trigger capability always to full oscilloscope bandwidth. In addition, it enables powerful trigger capabilities such as an adjustable trigger hysteresis.