Channel Access in Matlab

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Channel Access in Matlab
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What is matlab?

• Matlab is a programming language designed for
  data analysis.
• It comes with an integrated development
  environment.
• Includes help, debugging and some GUI
  functionality.
• It can be extended with self written functions
  and libraries.
• We provide an EPICS interface for matlab.
• Support from the controls section is only
  rudimentary.

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EPICS access in matlab

• Start matlab matlab
• Read value
• caget 'ARIDI-PCTCURRENT'
• returns structure val, sevr, stat, time,
  sevr_str, stat_str, time_str
• status, severity, timestamp available as numbers
  and as strings
• Write value
• caput 'channel', value
• Create monitor is not yet supported.

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Problems with matlab and EPICS

• Why do I get "Undefined function or method
  'caget'"?
• Check environment variable MATLABPATH
• echo MATLABPATH
• /usr/local/epics/extensions/mca/usr/local/epics/
  extensions/lib/SL3-x86
• Check that EPICS is installed in
  /usr/local/epics.
• Why does matlab sometimes crash on exit after
  using EPICS?
• I don't know, but it seems to be harmless.
• Why is the timestamp wrong by 1 or 2 hours?
• IOC time is UTC, not local (summer) time.
• I don't know how to handle time zones in matlab.
  Do you?

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Where can I learn more about matlab?

• Start matlab and click on MATLAB help
• Look at www.mathworks.de
• Ask one of the matlab experts
• Thomas Schilcher
• Mirek Dach
• For the basic matlab-EPICS interface see
  ics-web1.sns.ornl.gov/kasemir/mca
• For the caget, caput, camon wrapper functions ask
• Dirk Zimoch