Difference between revisions of "EPICS for Dummies"
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* Each record type performs a specific function | * Each record type performs a specific function | ||
* Records are customizable via fields that allow users to configure how they behave and monitor their state. | * Records are customizable via fields that allow users to configure how they behave and monitor their state. | ||
* Records vary significantly in complexity | * Records vary significantly in complexity; one way to classify them would be (*): | ||
** Simple records are associated with individual data types | ** Simple records are associated with individual data types | ||
*::;bi, bo, mbbi, mbbo, longin, longout, ai, ao, stringin, stringout, waveform | *::;bi, bo, mbbi, mbbo, longin, longout, ai, ao, stringin, stringout, waveform | ||
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** Flexible records allow custom functionality to be implemented | ** Flexible records allow custom functionality to be implemented | ||
*::;sub, aSub, luascript | *::;sub, aSub, luascript | ||
(*) not an official classification, nor an exhaustive list of record | |||
Revision as of 16:23, 10 February 2023
What is EPICS?
EPICS (Experimental Physics and Industrial Control System) is a distributed control system, which means that the IOC (software) can run on a different computer as the user interfaces.
What is an IOC?
IOC (Input/Output Controller) is a piece of software running on a computer:
- serves something called process variables (PVs) that you can read and write to
- used to run on VMEs, but nowadays it runs on anything.
- usually talks to hardware, but that isn’t a requirement.
What is a PV?
PV (Process Variables) is a the field from a record: PV = record_name + . + field_name
Most of the interactive parts of user displays have PVs associated with them.
What is a record?
Records are the building blocks of EPICS
- Each record type performs a specific function
- Records are customizable via fields that allow users to configure how they behave and monitor their state.
- Records vary significantly in complexity; one way to classify them would be (*):
- Simple records are associated with individual data types
- bi, bo, mbbi, mbbo, longin, longout, ai, ao, stringin, stringout, waveform
- Intermediate records often perform calculations or link multiple records
- calcout, scalcout, acalcout, swait, transform, fanout, dfanout
- Complex records are associated with devices or higher-level functionality
- motor, scaler, mca, sscan, table, digitel, vs
- Flexible records allow custom functionality to be implemented
- sub, aSub, luascript
(*) not an official classification, nor an exhaustive list of record