Mask Testing 16
Keysight InfiniiVision 3000T X-Series Oscilloscopes User's Guide 287
 
How is mask testing done?
InfiniiVision oscilloscopes start mask testing by creating a database that is 200 x 
640 for the waveform viewing area. Each location in the array is designated as 
either a violation or a pass area. Each time a data point from a waveform occurs in 
a violation area a failure is logged. If Test All was selected, every active analog 
channel is tested against the mask database for each acquisition. Over 2 billion 
failures can be logged per-channel. The number of acquisitions tested is also 
logged and displayed as "# of Tests".
The mask file allows greater resolution than the 200 X 640 database. Some 
quantization of data occurs to reduce the mask file data for display on-screen.
Although a mask can have up to 8 regions, in any given vertical column, it is only possible to 
define 4 regions. When there are 4 regions in a vertical column, one region must be tied to the 
top (using the MAX y value) and one must be tied to the bottom (using the MIN y value).