View source for EPICS

{{short description|Software infrastructure for building distributed control systems}}
{{External links|date=December 2020}}
{{Infobox Software
| name = EPICS
| logo = EPICS logo.svg
| developer = [[Free software community]]
| released = {{start date|1994|1|19}}
| latest_release_version = 3.15.8
| latest_release_date = {{release date and age|2020|05|15}}
| latest_preview_version = 7.0.4.1
| latest_preview_date = {{release date and age|2020|08|14}}
| programming language = C/C++, Perl
| operating_system = [[Cross-platform]]
| genre = [[Open-source software|Open Source]]
| license = [https://epics-controls.org/epics-open-license EPICS Open License]
| website = {{url|https://epics-controls.org/}}
}}
The '''Experimental Physics and Industrial Control System''' ('''EPICS''') is a set of software tools and applications used to develop and implement [[Distributed control system|distributed control systems]] to operate devices such as [[Particle accelerator|particle accelerators]], [[Telescope|telescopes]] and other large scientific facilities. The tools are designed to help develop systems which often feature large numbers of [[Computer network|networked computers]] delivering control and feedback. They also provide [[SCADA]] capabilities. 

== History ==
EPICS was initially developed as the Ground Test Accelerator Controls System (GTACS) at [[Los Alamos National Laboratory]] (LANL) in 1988 by Bob Dalesio, Jeff Hill, et al.<ref>{{Cite journal |last1=Kozubal |first1=A. J. |last2=Kerstiens |first2=D. M. |last3=Hill |first3=J. O. |last4=Dalesio |first4=L. R. |date=1990 |title=Run-time environment and application tools for the ground test accelerator control system |journal=Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment |language=en |volume=293 |issue=1–2 |pages=288–291 |doi=10.1016/0168-9002(90)91446-I|bibcode=1990NIMPA.293..288K }}</ref>&nbsp; In 1989, Marty Kraimer from Argonne National Laboratory (ANL) came to work alongside the GTA controls team for 6 months, bringing his experience from his work on the Advanced Photon Source (APS) Control System to the project. The resulting software was renamed EPICS and was presented at the International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS) in 1991.<ref>{{Cite web |url=https://epics.anl.gov/EpicsDocumentation/EpicsGeneral/EPICS_Architecture.pdf |title=EPICS Architecture |last= |first= |date= |website=EPICS – Experimental Physics and Industrial Control System |archive-url= |archive-date= |access-date=}}</ref>

EPICS was originally available under a commercial license, with enhanced versions sold by [[Tate & Kinetic Systems]]. Licenses for collaborators were free, but required a legal agreement with LANL and APS. An EPICS community was established and development grew as more facilities joined in with the collaboration. In February 2004, EPICS became freely distributable after its release under the EPICS Open License.<ref>{{Cite web |url=https://epics-controls.org/epics-open-license/ |title=EPICS Open License |last= |first= |date= |website=EPICS – Experimental Physics and Industrial Control System |archive-url= |archive-date= |access-date=}}</ref>

It is now used and developed by over 50 large science institutions worldwide, as well as by several commercial companies.

==Architecture==
EPICS uses [[client–server]] and [[publish–subscribe]] techniques to communicate between computers.&nbsp;Servers, the “[[input/output]] controllers” (IOCs), collect experiment and control data in real time, using the measurement instruments attached to them.&nbsp;This information is then provided to clients, using the high-bandwidth Channel Access (CA) or the recently added pvAccess networking protocols that are designed to suit [[Real-time computing|real-time]] applications such as scientific experiments.

IOCs hold and interact with a database of "records", which represent either devices or aspects of the devices to be controlled.&nbsp;IOCs can be hosted by stock-standard servers or PCs or by [[VMEbus|VME]], [[MicroTCA]], and other standard [[embedded system]] processors.&nbsp;For "hard real-time" applications the [[RTEMS]] or [[VxWorks]] operating systems are normally used, whereas "soft real-time"&nbsp;applications typically run on [[Linux]] or [[Microsoft Windows]].

Data held in the records are represented by unique identifiers known as Process Variables (PVs).&nbsp;These PVs are accessible over the network channels provided by the CA/pvAccess protocol.

Many record types are available for various types of input and output (e.g., analog or binary) and to provide functional behaviour such as calculations.&nbsp;It is also possible to create custom record types. Each record consists of a set of fields, which hold the record's static and dynamic data and specify behaviour when various functions are requested locally or remotely. Most record types are listed in the [https://wiki-ext.aps.anl.gov/epics/index.php/RRM_3-14 EPICS record reference manual].

[[Graphical user interface]] packages are available, allowing users to view and interact with PV data through typical display widgets such as dials and text boxes.&nbsp;Examples include EDM (Extensible Display Manager), MEDM ([[Motif (software)|Motif]]/EDM), and [https://controlssoftware.sns.ornl.gov/css_phoebus CSS].

Any software that implements the CA/pvAccess protocol can read and write PV values.&nbsp;Extension packages are available to provide support for [[MATLAB]], [[LabVIEW]], [[Perl]], [[Python (programming language)|Python]], [[Tcl]], [[ActiveX#ActiveX|ActiveX]], etc. These can be used to write scripts to interact with EPICS-controlled equipment.

==Facilities using EPICS==
{| class="wikitable"
|+
List of Institutions using EPICS, by Region
!Region
!Institute
!Country
|-
|Africa
|[[iThemba LABS]]<ref>[http://www.tlabs.ac.za iThemba LABS - South Africa]</ref>
|South Africa
|-
| rowspan="8" |Asia
|[[KSTAR]] – Korea Superconducting Tokamak Advanced Research
|Republic of Korea
|-
|[[J-PARC]] – Joint Facility for High Intensity Proton Accelerators
| rowspan="4" |Japan
|-
|[[Electron_scattering#RIKEN_RI_Beam_Factory|RIBF]] – RIKEN RI Beam Factory Project
|-
|[[KAGRA]] – Kamioka Gravitational Wave Detector
|-
|[[SuperKEKB]] at KEK in Tskuba
|-
|BSRF - [[Beijing Synchrotron Radiation Laboratory]]<ref>[http://english.bsrf.ihep.cas.cn Beijing Synchrotron Radiation Laboratory (BSRF)] </ref>
|China
|-
|[[Variable Energy Cyclotron Centre|VECC]] – Variable Energy Cyclotron Centre
| rowspan="2" |India
|-
|[https://www.tifrh.res.in/ TIFR]- Tata Institute of Fundamental Research
|-
| rowspan="17" |Europe

|[[BESSY|Berliner Elektronenspeicherring für Synchrotronstrahlung (BESSY II)]] – [[Helmholtz-Zentrum Berlin]]
| rowspan="7" |Germany
|-

|[[DESY|Deutsches Elektronen Synchrotron (DESY)]]
|-
|[http://fel.fhi-berlin.mpg.de FHI free-electron laser (FEL)] - [[Fritz Haber Institute of the Max Planck Society]]
|-
|[[GEO600]] – [[Gravitational-wave observatory]], [[Max Planck Institute for Gravitational Physics]]
|-
|[http://www.gsi.de/fair/ GSI/FAIR]
|-
|[https://www.ikp.tu-darmstadt.de/sdalinac_ikp/ S-DALINAC] – [[Technische Universität Darmstadt]]
|-
|[[Wendelstein 7-X]] – experimental [[stellarator]], [[Max Planck Institute of Plasma Physics]]
|-
|[[Diamond Light Source]] – [[Rutherford Appleton Laboratory]]
| rowspan="3" |United Kingdom
|-
|[[ISIS neutron source|ISIS Neutron Source]] - [[Rutherford Appleton Laboratory]]
|-
|[[International Muon Ionization Cooling Experiment|International Muon Ionization Cooling Experiment (MICE)]] – [[Rutherford Appleton Laboratory]]
|-
|[[European Spallation Source]] [[European Research Infrastructure Consortium|ERIC]] (ESS)
|Sweden
|-
|[[ITER|International Thermonuclear Experimental Reactor (ITER)]]
| rowspan="2" |France
|-
|Spiral2 Système de Production d'Ions RadioActifs en Ligne de deuxième génération
|-
|[[Laboratori Nazionali di Legnaro]]
|Italy
|-
|[[Swiss Light Source]] – [[Paul Scherrer Institut]]
|Switzerland
|-
|[[SwissFEL]] – [[Paul Scherrer Institut]]
|Switzerland
|-
|[[TARLA|Turkish Accelerator and Radiation LAboratory]]  ([[TARLA]])
|Turkey
|-
|Middle East
|[[Synchrotron-Light for Experimental Science and Applications in the Middle East]] (SESAME)
|Jordan
|-
| rowspan="20" |North America
|[[Advanced Light Source]] – [[Lawrence Berkeley National Laboratory]]
| rowspan="17" |United States
|-
|[[Advanced Photon Source]] – [[Argonne National Laboratory]]
|-
|[[Apache Point Observatory]]
|-
|[[FNAL]] – [[Fermi National Accelerator Laboratory]]
|-
|[[Facility for Rare Isotope Beams]] – [[Michigan State University]]
|-
|[[Gemini Observatory]]
|-
|[[W. M. Keck Observatory]]
|-
|[[LIGO|Laser Interferometer Gravitational-Wave Observatory (LIGO)]]
|-
|[[Los Alamos Neutron Science Center]] – [[Los Alamos National Laboratory]] 
|-
|[[National Spherical Torus Experiment]] – [[Princeton Plasma Physics Laboratory]]
|-
|[http://nstx-u.pppl.gov National Spherical Torus Experiment Upgrade] – [[Princeton Plasma Physics Laboratory]]
|-
|[[National Superconducting Cyclotron Laboratory]] – [[Michigan State University]]
|-
|[[National Synchrotron Light Source II]] – [[Brookhaven National Laboratory]]
|-
|[[Spallation Neutron Source]] – [[Oak Ridge National Laboratory]]
|-
|[[Stanford Synchrotron Radiation Laboratory]] – [[Stanford University]]
|-
|[[SLAC_National_Accelerator_Laboratory#LCLS|Linac Coherent Light Source]]  – [[SLAC National Accelerator Laboratory]]
|-
|[[TJNAF]] – [[Thomas Jefferson National Accelerator Facility]]
|-
|[[Canadian Light Source]] – [[Saskatoon, Saskatchewan]]
| rowspan="3" |Canada
|-
|[[Canadian Neutron Beam Centre]] – [[Chalk River Laboratories]] 
|-
|[[TRIUMF]] – Located on the campus of the [[University of British Columbia]]
|-
|Not determined
|[[IFMIF]] – [[International Fusion Materials Irradiation Facility]]
|European Union
Japan

United States

Russia
|-
| rowspan="4" |Oceania
|[[Australian Synchrotron]]
| rowspan="4" |Australia
|-
|[[ANTARES (accelerator)|ANTARES]] – [[ANSTO|Australian Nuclear Science and Technology Organisation]]
|-
|[[Australian Square Kilometre Array Pathfinder|ASKAP (Australian Square Kilometre Array Pathfinder)]] – [[CSIRO]]
|-
|[https://physics.anu.edu.au/nuclear/hiaf.php Heavy Ion Accelerator] at the [[Australian National University]]
|-
|South America
|[[Laboratório Nacional de Luz Síncrotron|LNLS – Laboratório Nacional de Luz Síncrotron]]
|Brazil
|}

== Commercial Users ==

* [https://www.bira.com BiRa Systems]
*[http://ciemat.es Ciemat] {{Webarchive|url=https://web.archive.org/web/20190904044754/http://www.ciemat.es/ |date=2019-09-04 }}
* [http://cosylab.com CosyLab]
* [http://gl-research.com GLResearch]
* [http://idtnet.co.uk idt]
*[http://mobiis.com/en/technology/ Mobiis]
* [https://nusano.com Nusano, Inc]
* [http://observatorysciences.co.uk Observatory Sciences]
* [http://ospreydcs.com Osprey Distributed Control Systems]
* [[Varian Medical Systems]]
* [https://ptcusa.com Pyramid Technical Consultants]

==See also==
{{Portal|Free and open-source software}}
* [[TANGO]] control system
* [[SCADA]]—Supervisory Control And Data Acquisition

== References ==
<references />

==External links==
{{Div col|colwidth=}}
*{{Official website|https://epics-controls.org/}}
*[https://wiki-ext.aps.anl.gov/epics/index.php/RRM_3-14 EPICS Record Reference Manual]{{div col end}}
[[Category:Science software]]
[[Category:Physics software]]
[[Category:Experimental particle physics]]
[[Category:Industrial automation software]]