Tektronix CSA8000B - Manual (Page 218)

Using Masks, Histograms, and Waveform Databases
3- 144 CSA8000B & TDS8000B User Manual
These points form
the bottom of the mask
These points form
the top of the mask
Left-most point
Right-most point
Top/bottom dividing line
(not displayed)
Figure 3- 26: Creating a user mask
Note in Figure 3--27 that a new vertex has been added to the mask shown in
Figure 3--26. Since the point is added above the line, it’s added to the top.
User added vertex
Figure 3- 27: Adding a new vertex