Tektronix DPO2304SX, Printable Help

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Standards and bandwidth. When the instrument system bandwidth (which includes the instrument, attached probes, and/or
cabling) falls into the range of 1.5 to 1.8 (0.8 for optical signals) times the data signal bit rate, the third harmonic of the data signal
is significantly attenuated. The instrument displays useful qualitative information, but quantitative rise-time measurements under
these conditions may not be accurate.
For example, a FC531E Elec mask has a bit rate of 531.25 Mb/s; 1.5 to 1.8 times this value is a range of 796.5 MHzBW to
955.8 MHzBW. Therefore, you should not use an instrument with less than 1 GHz measurement system for making quantitative
rise-time measurements of this standard.
When just the instrument bandwidth falls within 1.5–1.8 (0.8 for optical signals) times the bit rate of a selected mask standard, the
instrument displays the message "Consider system bandwidth when testing at this bit rate." in the status area above the
graticule.
What do you want to do next?
Learn more about eye measurements.
Learn about communication triggering.
Go to mask testing setup overview.
Serial mask testing with mask testing
The Serial Mask Testing option provides electrical mask testing on communication standards and communication triggering.
Mask testing consists of two tasks: signal violation detection and pass/fail testing. Signal violation detection lets you test
communications signals for time or amplitude violations against a predefined mask. Each mask consists of one or more
polygonal regions called segments. The signal waveform data should stay outside of the segments defined by the mask. Any
signal data that occurs inside a mask segment is called a mask segment violation or "hit."
You can select from any of the included standard telecommunications masks, or you can define your own custom masks.
Selecting a mask automatically sets the instrument communications triggers to properly display most communication signals in
the mask.
Pass/Fail testing defines the mask testing parameters, including the number of waveforms to test, how many mask hits are
allowed before failing a test, setting a mask margin tolerance value, and what action to perform upon the completion or failure of
a test.
Communication triggering enables you to trigger on and display waveforms for industry-standard communications signals. See
Mask Types and Standards for a list of the supported standards on which you can trigger.
Automatic communication signal measurements enable you to make automatic measurements on communications signals. See
the
Communication Measurement tab in the Measurement setup window for the available measurements.
The following are Serial Mask Testing key features:
■ Predefined masks for testing or triggering on industry-standard signals, such as ITU-T G.703, ANSI T1.102, Fibre Channel,
Ethernet, Video, SONET, Rapid IO, USB, IEEE 1394b, OIF Standards and their subsets
■ Autoset, which quickly adjusts the instrument vertical and horizontal controls to display a waveform in a mask
■ Autofit, which positions the signal on each acquisition to minimize mask segment hits
■ Mask margins, which allow you to adjust the default mask margin tolerances
■ Pass/Fail testing to continuously test a specified number of waveforms against a mask
■ A mask editor for creating, saving, and recalling user-defined masks
■ Waveform database technology to perform mask testing based on waveforms accumulated in a database, rather than a
single waveform stored in acquisition memory
■ Communications triggers to trigger the instrument on industry-standard communications signals
Oscilloscope reference
DPO70000SX, MSO/DPO70000DX, MSO/DPO70000C, DPO7000C, and MSO/DPO5000B Series 739