Mask Testing
Mask limit testing is a feature that indicates if a signal goes outside a specified area, called a mask. PicoScope can draw the mask automatically by tracing a captured signal. Mask limit testing is useful for spotting intermittent errors or errors of specific value.

Masks can be found by going into Tools-> Masks and then Add Mask.

The next screen that appears is the “Mask Library”. First select the appropriate channel and then click the “Generate” button. This will bring up a window where the name of the mask can be defined and how much clearance in the X and Y directions is required by using the up and down arrows or typing in a specific value.

The adjustments can also be made in % by clicking the SI button and can be changed back to SI units by clicking the % button.

Once the appropriate settings are defined, click on the Generate button. The mask will appear in the list under Library.

Highlighting the mask and clicking on Apply will apply the mask to the view.

The measurements appear at the bottom giving the number of mask failures along with some other statistics.

The mask failures can be searched through in the waveform buffer. However, with a large number of waveforms, it can be difficult to search through.

A useful way to search through these waveforms is to select "Mask Failures on Channel X" in the buffer overview.

This makes it much easier to search through the waveform buffers and the failed waveforms can be viewed immediately.
Saving and Clearing Masks
Once a mask is created it is saved automatically into the PicoScope settings so the next time PicoScope is loaded the mask will appear in the library. Masks can also be saved for use on other machines, by going into Tools->Masks->Save Mask.

The file format is .mask and by default the location is selected is the “Waveforms” document under “My Documents”.
A mask can be cleared by clicking on Tools->Masks-> Clear Mask.