Agilent Technologies 86100A, Programmer'S Manual, Page: 230 / 366

17-2
Mask Test Commands
Mask Test Commands
The Mask Test commands and queries control the mask test features. Mask testing automati-
cally compares measurement results with the boundaries of the mask you select. Any wave-
form or sample that falls within the boundaries of the mask is recorded as a failure.
N O T E Compatibility with the Agilent 83480A/54750A. In commands with a REGion parameter, POLYgon may be used
in place of REGion for compatibility with the Agilent 83480A/54750A.
For histograms, mask testing, and color grade-gray scale display, the instrument uses a spe-
cific database. This database uses a different memory area than the waveform record for each
channel. When any of the histograms, mask testing, and color grade-gray scale display fea-
tures is turned on, the instrument starts building the database. The database is the size of the
graticule area, which is 321 pixels high by 451 pixels wide. Behind each pixel is a 16-bit
counter. Each counter is incremented each time a pixel is hit by data from a channel or func-
tion. The maximum count (saturation) for each counter is 63,488. You can check to see if any
of the counters is close to saturation by using the :MEASure:CGRade:PEAK? query. The
color-graded display uses colors to represent the number of hits on various areas of the dis-
play.
The database continues to build until the instrument stops acquiring data or all three func-
tions (color grade-gray scale display, mask testing, and histograms) are turned off. The
instrument stops acquiring data when the power is cycled, the Stop/Single hardkey is
pressed, after a specified number of waveforms or samples are acquired, or as another mod-
ule is plugged in.
You can clear the database by pressing the Clear Display hardkey, cycling the power, turning
off all three features that use the database, or sending a CDISplay command.
Before firmware revision 3.00, the database does not differentiate waveforms from different
channels or functions. If three channels are turned on and the waveform for each channel
happens to light the same pixel at the same time, the counter is incremented by three. How-
ever, you cannot tell how many hits came from each waveform. For this reason, mask test is
available in Eye/Mask mode only, which allows only one channel to function at a time. For
firmware revisions 3.00 and above multiple data bases are supported.
To avoid erroneous data, clear the display after you change instrument setup conditions or
device under test (DUT) conditions and acquire new data before extracting measurement
results.
The instrument provides a series of standard masks defined according to telecom and data-
com standards. For a complete list of masks and templates, refer to the online Help. Load a
mask file using the DISK:LOAD or :MTESt:LOAD commands. Mask files have the
.msk or
.pcm extensions.