Allen-Bradley 2080-LC20-20AWB, User Manual

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Rockwell Automation Publication 2080-UM005E-EN-E - March 2018
Chapter 9 Using microSD Cards
Data Log
The data logging feature allows you to capture global and local variables with
timestamp from the Micro800 controller into the microSD card. You can retrieve
the recorded datasets on the microSD card by reading the contents of the
microSD card through a card reader or by doing an upload through the
Connected Components Workbench software.
A maximum number of 10 datasets is supported for a Micro820 program. Each
dataset can contain up to 128 variables, with a maximum of four (4) data string
variables per dataset. String variables can have a maximum of 252 characters. All
datasets are written to the same file. For more information on how data logs are
stored on the microSD card, see the Data Log Directory Structure on page 107 .
You can retrieve data log files from the microSD card using a card reader or by
uploading the data logs through Connected Components Workbench.
See the sample quickstart project to get you started on the Data Log feature, Use
the Data Log Feature on page 116 .
IMPORTANT
Uploading data log files in PROGRAM mode is recommended for
optimum performance and to prevent file access conflict. For example, if
the data log instruction is executing, Connected Components Workbench
will not upload the last data log file.
IMPORTANT
Data log execution time depends on the user application and its
complexity. Users are advised to data log
no faster than every two
seconds for typical applications. Note that housekeeping takes at least
5 ms per program scan. See Program Execution in Micro800 on page 73
for more information on program scan and execution rules and sequence.
See also
Data Log – Data Payload vs. Performance Time on page 136 .
IMPORTANT
Note that in cases where there are simultaneous RCP and DLG function
block execution or uploads/downloads/searches, the activities are
queued up and handled one by one by the program scan. Users will
notice a slowdown in performance in these cases.