Hysteresis triggers eliminate incorrect triggers caused by noisy signals. For example, if your signal contains two rising edges of different amplitudes, you can use hysteresis triggering to trigger on one of the edges. Although NI-SCOPE uses a default amount of hysteresis for edge triggering, which is typically 2.5% of the vertical range, you can override that value by setting your own hysteresis values. The Configure Trigger Hysteresis function or VI allows you to choose the trigger coupling, trigger level, hysteresis value, and trigger slope.
Hysteresis triggering is possible on all analog trigger channels, such as 0, 1, or the external trigger input.
A positive slope hysteresis trigger is generated when the signal crosses below the voltage specified by the trigger level parameter minus the hysteresis value, and then crosses the trigger level.
A negative slope hysteresis trigger is generated when a signal crosses above the voltage specified by the trigger level parameter plus the hysteresis value, and then crosses the trigger level.