High and low level trigger

The analogue trigger input is continuously sampled at the selected sample rate. If the user programmed level is exceeded by the trigger signal, then the trigger is seen as valid and acted upon. The green trace shows when the condition has been met for a valid trigger. During recording further triggers are ignored until the recording period has completed. A programmed level is simply made by the programmer in the appropriate register of the driver software. Level triggers. Diagram showing trigger following its signal exceeding set level.
This level trigger also works for low level situations, that is when the trigger signals falls below the programmed level. Level triggers. Diagram showing trigger following its signal dropping below a set level.
Note that in both diagrams above the "Start" indicates the point at which the card was armed ready to receive triggers, here the start occurred when the trigger condition was already fulfilled, so instantly the card starts to record. The "Start" could be at any point in time as determined by the user and his application.

This trigger mode can be combined with AND or OR logic from other sources, e.g. a software trigger (such as key press), from the LVTTL trigger input connector, or the actual analogue signal you wish to record. The above is just a summary of the versatile window trigger features. Full details of the trigger operation can be found in the user manual.

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