Author: Johnson, A.N.
Paper Title Page
WEPKS020 Adding Flexible Subscription Options to EPICS 827
  • R. Lange
    HZB, Berlin, Germany
  • L.R. Dalesio
    BNL, Upton, Long Island, New York, USA
  • A.N. Johnson
    ANL, Argonne, USA
  Funding: Work supported by U.S. Department of Energy (under contracts DE-AC02-06CH11357 resp. DE-AC02-98CH10886), German Bundesministerium für Bildung und Forschung and Land Berlin.
The need for a mechanism to control and filter subscriptions to control system variables by the client was described in a paper at the ICALEPCS2009 conference.[1] The implementation follows a plug-in design that allows the insertion of plug-in instances into the event stream on the server side. The client can instantiate and configure these plug-ins when opening a subscription, by adding field modifiers to the channel name using JSON notation.[2] This paper describes the design and implementation of a modular server-side plug-in framework for Channel Access, and shows examples for plug-ins as well as their use within an EPICS control system.
[1] R. Lange, A. Johnson, L. Dalesio: Advanced Monitor/Subscription Mechanisms for EPICS, THP090, ICALEPCS2009, Kobe, Japan.
[2] A. Johnson, R. Lange: Evolutionary Plans for EPICS Version 3, WEA003, ICALEPCS2009, Kobe, Japan.
poster icon Poster WEPKS020 [0.996 MB]