User manual

WaveSurfer 3000 Oscilloscopes
Dropout Trigger
Dropout triggers when a signal loss is detected. The trigger is generated at the end of the timeout period
following the last edge transition that meets the trigger conditions. It is used primarily in single-shot
applications with a pre-trigger delay.
On the Trigger dialog, select Smart trigger type, then Dropout to display the controls.
ANALOG DROPOUT
1. Choose the Source signal input.
2. Choose the type of signal Coupling at the input. Choices are:
l DC - All the signal’s frequency components are coupled to the trigger circuit for high frequency
bursts or where the use of AC coupling would shift the effective trigger level.
l AC - The signal is capacitively coupled. DC levels are rejected, and frequencies below 10 Hz are
attenuated.
l LFREJ - The signal is coupled through a capacitive high-pass filter network, DC is rejected and
signal frequencies below 400 kHz are attenuated. For stable triggering on medium to high
frequency signals.
l HFREJ - Signals are DC coupled to the trigger circuit, and a low-pass filter network attenuates
frequencies above 1 MHz (used for triggering on low frequencies).
3. Choose the Slope (edge) and enter the voltage Level to watch for transitions. Where available, the Find
Level button sets the Level to the signal mean.
4. Under Dropout Condition is..., enter the time interval after which to trigger if no transition occurs at that
Slope and Level.
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