Transcript Channel Access in Matlab

Channel Access in Matlab
Advanced EPICS Training, Dirk Zimoch 2008
Channel Access in Matlab
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.
Advanced EPICS Training, Dirk Zimoch 2008
Channel Access in Matlab
EPICS access in matlab
■ Start matlab: matlab
■ Read value
caget 'ARIDI-PCT:CURRENT'
►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.
Advanced EPICS Training, Dirk Zimoch 2008
Channel Access in Matlab
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?
Advanced EPICS Training, Dirk Zimoch 2008
Channel Access in Matlab
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
Advanced EPICS Training, Dirk Zimoch 2008