Elmo HARmonica, HARSFEN0602 software manual Trigger delay, Slope and window trigger types

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Figure 1 - Slope and window trigger types

- Triggered by digital signal: The Harmonica will support this only in the future, TBD.

Trigger delay

The trigger defines when the recorder is to start. The recorder can be told to start before the trigger event, so that the trigger event can be caught in “the middle of the picture”. This is possible since the recorder starts to record at the instance it is launched by the RR command, so that when the trigger event occurs, the pre-trigger information is already recorded.

The following picture examples this. The recorded signal is the speed. The trigger is set on BG. After launching the recorder with RR=3, the command sequence JV=5000;BG is entered. The results are shown in the picture below.

Note that in the above example, the recorder works for 10sec. Therefore, a pre-trigger delay of 20% requires 2 seconds to acquire the pre-trigger data. A BG command that is set less than 2 seconds after the RR=3 will be missed.

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