CompuScope SDK for L.. - Egmont Instruments

As an example, consider a signal where the feature of interest is 20,000 samples long butbegins 100,000 samples after the trigger event. In this case, the SegmentSize and Depthshould be set to 20,000. The Trigger Delay value should be set to 100,000. Without theTrigger Delay feature, the user would be forced to set the Depth to 120,000 Samples andwaste 100,000 Samples of memory, even though only the last 20,000 were downloaded.Using the Trigger Delay feature, however, only the data of interest are retained inCompuScope memory.CompuScope Acquisition Timing DiagramThe timing diagram below is provided as an aid for understanding the timing of eventsduring the acquisition of a segment or record. The pseudo—signals are indicated asHIGH when the labeled function is active.A CompuScope system always acquires from the beginning of the Segment Start pulseand continues until the Depth counter’s count-down has expired. The memory allotted tothe acquisition is equal to the Segment Size and is arranged in a circular fashion. Noticethat raw trigger events are ignored until the Trigger Holdoff time has elapsed.Note also that, although pre-trigger data are acquired throughout the time betweenSegment Start and the Trigger Event, most of the acquired pre-trigger data have beenoverwritten in the diagram below and only a small fraction are available for download.CompuScope SDK for LabVIEW for Windows 29