User manual

Mask Testing
R&S
®
RTO
215User Manual 1316.0827.02 ─ 06
8 Mask Testing
8.1 About Mask Testing
Masks are used to determine whether the signal remains within specified limits, e.g. to
uncover signal anomalies or test compliance and stability of digital signals. The limits are
specified as "mask", which is laid over the input signal in the display. Thus you can easily
detect where the signal violates the mask.
Mask testing with R&S RTO has only a minor impact on the acquisition rate, thus mask
violations are detected very fast and reliably.
With R&S RTO, you can define own masks easily. Specific actions can be executed when
mask violations occur. For error analysis, you can stop the acquisition on a failed test and
use the history view to look at the previous waveforms.
Mask test
A mask test consists of:
●
Mask definition
●
Waveform to be tested
●
Fail criteria for test
●
Actions to be taken on violation or successful completion
Mask Definition
A mask can be created in several ways:
●
The individual mask points are defined, either on the touch screen or as numerical
values. This mask type is called user mask.
For details, see chapter 8.3.2.1, "Mask Definition: User Mask", on page 227.
●
The mask is derived from an existing waveform. This mask type is called waveform
mask.
For details, see chapter 8.3.2.2, "Mask Definition: Waveform Mask", on page 230.
Fail Criteria for Testing
The fail criteria for a mask test is set by two parameters: "Fail condition" and "Violation
tolerance". Fail condition defines if sample hits or the number of acquisitions with sample
hits are considered. Violation tolerance sets the number of tolerable sample hits or acqui-
sition hits. A test has failed if the number of sample hits or acquisition hits exceeds the
limit of violation tolerance hits.
See also: "Fail condition, Violation tolerance" on page 226.
8.1.1 Results of a Mask Test
The result box of a mask test shows the following test results:
About Mask Testing