Navigation:  Tutorials > Basic tutorials > Storage options > DEWESoft 7.0  data acquisition, processing, analyzing and storage software Fast on trigger

If our data consists of events which can be captured, we can choose to store it as fast on trigger. The trigger event can be defined in the software and then DEWESoft will wait for this event and store only the portion of interest.

This can be set by choosing the fast on trigger storing option. After doing this, the new tab Trigger will appear where we are able to set up the trigger condition and strategy.

First we can choose to define the pre-time, post-time and holdoff-time.
Pre time is the time which will be stored before the trigger event occurs. We define the 100 ms before an event as the pre-trigger. This means that DEWESoft will keep the data in the buffer until the trigger event occurs and then store this data to the file in addition to the regular data.
Post time is the time after trigger event which will be stored. If this is not defined, DEWESoft will continue to store until we stop it manually or a stop condition occurs. For this example, we want to capture trigger shots, so the post trigger should be set to 200 ms, so a total of 300 ms of data will be captured per trigger event.

Now we need to define the trigger conditions for the beginning of storage. Let's add one trigger condition by clicking setup to define it.

 

In the trigger setup window, we can choose channels for triggering. We can select several channels for triggering, but since this example deals only with one, there is only one choice. Then, define the trigger criteria needs to be defined. The user can trigger on time data, time or FFT.
Time triggering includes edge, filtered edge, window, pulse-width... on real data, average or RMS values. For this simple application, only the simple edge with a trigger level of 0.5 will be selected. This means that when the value crosses the 0,5 V limit, it will produce a trigger. One can already test the behavior of the trigger from the scope in the lower left side of the setup window.

 

Now let's take some measurements. The user just needs to hit the microphone to produce the necessary trigger. We can see from the recorder that the first shot was not high enough, therefore we hit it harder. That did it, and one we can see the beginning of the storage event, the trigger event and the end the of storage event.

Note that the Store button changed the name to Arm and there is an additional Trig button . This is manual trigger to issue a to trigger even without an event.

 

Let's review the data being stored. We can see that only the trigger events are stored, yet for the rest of time the data is blank. Note that there is a new button, called TRIGGER MODE, in the data preview. This gives us a chance to review the trigger events without zooming in on the data. If it is clicked, the first trigger event is automatically zoomed in.

 

The trigger mode button changes to an "arrows" button, where we can browse between the events. If those two buttons are clicked, the recorder shows the trigger events one by one. On the data preview we can see the currently selected trigger event. Right click on the recorder to zoom out to the full region and to leave trigger mode.

 

Note that there was had one peak in the beginning of storage. It was not enough to be stored with the trigger, but sometimes it is still nice to see what the values in the regions without the trigger event were.