Delay (Playback Trigger)
determines the amount of time used for playback trigger delay for a measurement.
If delay is zero, the measurement hardware takes data immediately after detecting a valid trigger signal. If delay is positive (called post-trigger delay) or negative (called pre-trigger delay), the amount of delay determines when the time record begins with respect to the trigger signal.
can be set for these playback trigger styles:
Playback Trigger parameters (including this one) affect the outcome of the time record when making a measurement.
Pre-Trigger (negative) Delay
Pre-trigger delay indicates an amount of time before the trigger signal arrives. This is accomplished using sample memory (RAM). When a pre-trigger delay is selected, the measurement hardware stores the last X seconds of data in sample memory until it receives a valid trigger signal. The hardware then uses the stored data as part of the time capture to achieve the pre-trigger delay.
Pre-trigger delay is limited by the amount of sample memory available for the measurement and the frequency span.
Post-Trigger (positive) Delay
Post-trigger delay indicates how long after the trigger signal to start capturing data and is limited by the range of the trigger counter (which counts the time after trigger happens). This parameter is not affected by sample memory. Again, the time represented by this count depends on the time each sample represents, which varies with span.
See Also
