User Patterns - Agilent Technologies N4906B Serial BERT User Manual

Setting up Patterns
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User Patterns

User patterns are user-editable patterns that are written to the
Serial BERT's memory for pattern generation (see "How does the
Serial BERT Generate Patterns?" on page 19 for details). User
patterns can contain up to 32 Mbit of any arbitrary data pattern. They
may be generated by the Serial BERT software or defined in a pattern
file and loaded into the memory. The Serial BERT reads the memory
bit by bit, and generates the output accordingly.
The following topics explain how the Serial BERT works with user
patterns, and also explain how user patterns are generated.
NO TE
The way software-generated patterns (distorted PRBS, PRBN) are
output is identical to that of user patterns: The patterns are written to
the memory, and the output is generated from there. Some of the
information in these topics covers how the patterns are actually
generated, and thus also applies to software-generated patterns.
When to Test with User Patterns
Creating or editing patterns is necessary for quality testing because
different patterns present different data loads to the device. This can
cause variations in the bit error ratio. With user patterns, you can
define exactly the pattern used in the test.
Supported Pattern Types
The Serial BERT can import the following pattern types:
• HP/Agilent 71600 series patterns (*.dat file type).
• Patterns saved as ASCII files by the Serial BERT or the Agilent
86130 (*.ptrn and *.txt file type).
These are described in detail in "Pattern File Specifications" on
page 25.
The Serial BERT can save files as either *.dat, *.ptrn or *.txt files.
NO TE Downloading a text format pattern into your instrument may take
significantly longer than a binary pattern.
Agilent N4906B Serial BERT, User's Guide, October 2005
User Patterns