Rockwell Automation FactoryTalk Historian SE 3.0 H2H Interface User Guide - Manual (Page 114)

Buffering
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Buffering Settings
There are a number of settings that affect the operation of PIBufss and Bufserv. The
Buffering Settings page allows you to set these parameters. If you do not enter values for
these parameters, PIBufss and Bufserv use default values.
PIBufss
For PIBufss, the paragraphs below describe the settings that may require user intervention.
Please contact Rockwell Automation Technical Support for assistance in further optimizing
these and all remaining settings.
Primary and Secondary Memory Buffer Size (Bytes)
This is a key parameter for buffering performance. The sum of these two memory buffer sizes
must be large enough to accommodate the data that an interface collects during a single scan.
A typical event with a Float32 point type requires about 25 bytes. If an interface writes data
to 5,000 points, it can potentially send 125,000 bytes (25 * 5000) of data in one scan. As a
result, the size of each memory buffer should be 62,500 bytes.
The default value of these memory buffers is 32,768 bytes. Rockwell Automation
recommends that these two memory buffer sizes should be increased to the maximum of
2000000 for the best buffering performance.