Q

A

When pre samples are selected, the trigger system is immediately activated after starting the measurement. At the first occasion that the trigger conditions are met, the system will start measuring post samples. The system will not first fill the pre sample buffer before the trigger system is activated. Depending on the measured signal and the moment the measurement was started, this may result in a situation where not all pre samples are measured, but the first pre samples remain 0 Volt.

The reason this technique is used is that in this way never a trigger will be missed. If the system would first fill the pre samples buffer before activating the trigger system, it might happen that the event that should cause a trigger would take place while still filling the pre samples buffer and therefore not generate a trigger. No measurement will take place.

You can find more information on presamples and triggering in the classroom section.