Navigation:  Tutorials > Measurement tutorials > Voltage and current > DEWESoft 7.0  data acquisition, processing, analyzing and storage software Triggered storing

It is necessary to have high sampling rates (see previous chapter Channel setup) for the detection of glitches. These high sampling rates are related to the total waste of disk space. If the data is always stored fast, the user might end up with gigabytes of data, of which there might be only few seconds of useful data. Therefore, it makes sense to store the data only when something is happening. To do this, we should select the Fast on trigger storage option. The user can define the "start storing condition" , which is the level trigger when the voltage derivate exceeds 150 kV/s, as well as including Pre time and Post time . Pre time is the time that the data will be stored before the trigger occurred while the post time is the time after the event. If the post time is not defined, data will be stored until a there is a manual Stop or the Stop storing condition occurs (in this case, none was defined). For glitches, it is enough to have only some data before and after the event happened.

 

This is the manual way of setting the trigger. We can achieve the same by simply clicking the Lock trigger button in the Trigger section of the scope. This will use the current pre and post time, trigger source and trigger level.

Either way, we now have to set specific trigger criteria. Now it's time to store some data. When we click Store an additional button Trig becomes visible, which tells us that triggered storing is being used.
We can also click this button to a issue manual trigger.

Now let's make some trigger shots. These will appear in the scope, and the Trig button flashes.

 

When we open this file, the first trigger is immediately shown in the scope. However, the whole zoom area is selected (in the recorder, for example). Now, the user has to click the TRIGGER MODE button to view the data trigger by trigger.

 

Then this button changes to a "left" and "right" button . By clicking these buttons, the  user can browse through trigger events. One can also use the scope zoom to zoom in on specific regions of the trigger. The example below shows how a trigger on derivate reveals a small distortion in voltage really nicely.