User manual

WaveSurfer 3000 Oscilloscopes
Runt Trigger
Runt triggers when a pulse crosses a first threshold, but fails to cross a second threshold before re-crossing
the first. Other defining conditions for this trigger are the polarity and runt interval (width).
On the Trigger dialog, select Smart trigger type, then choose Runt to display the controls.
1. Choose the Source 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 Polarity on which to measure.
4. Enter the voltage crossing Upper Level and Lower Level. Where available, the Find Level button sets the
levels to the positive and negative signal mean.
5. Use Time Condition is settings to create an expression describing the runt interval (width). This condition
is in addition to (AND) the voltage crossing levels. The interval may be:
l Any width Less Than an Upper Interval.
l Any width Greater Than a Lower Interval.
l Any width In Range or Out Range of values. You may describe the range using either:
l Limits, an absolute Upper Interval and Lower Interval.
l Delta, any Nominal width plus or minus a Delta width.
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