Author: Patrick, J.F.
Paper Title Page
MOPPC149 A Messaging-Based Data Access Layer for Client Applications 460
 
  • J.F. Patrick
    Fermilab, Batavia, USA
 
  Funding: US Department of Energy
The Fermilab Accelerator Control system has recently integrated use of a publish/subscribe infrastructure as a means of communication between Java client applications and data acquisition middleware. This supercedes a previous implementation based on Java Remote Method Invocation (RMI). The RMI implementation had issues with network firewalls, misbehaving client applications affecting the middleware, lack of portability to other platforms, and cumbersome authentication. The new system uses the AMQP messaging protocol and RabbitMQ data brokers. This decouples the client and middleware, is more portable to other languages, and has proven to be much more reliable. A Java client library provides for single synchronous operations as well as periodic data subscriptions. This new system is now used by the general synoptic display manager application as well as a number of new custom applications. Also a web service has been written that provides easy access to control system data from many languages.
 
poster icon Poster MOPPC149 [4.654 MB]  
 
TUPPC070 Detector Controls for the NOvA Experiment Using Acnet-in-a-Box 740
 
  • D.J. Nicklaus, L.R. Carmichael, D. Finstrom, B. Hendricks, CA. King, W.L. Marsh, R. Neswold, J.F. Patrick, J.G. Smedinghoff, J. You
    Fermilab, Batavia, USA
 
  In recent years, we have packaged the Fermilab accelerator control system, Acnet, so that other instances of it can be deployed independent of the Fermilab infrastructure. This encapsulated "Acnet-in-a-Box" is installed as the detector control system at the NOvA Far Detector. NOvA is a neutrino experiment using a beam of particles produced by the Fermilab accelerators. There are two NOvA detectors: a 330 ton ‘‘Near Detector'' on the Fermilab campus and a 14000 ton ‘‘Far Detector'' 735 km away. All key tiers and aspects of Acnet are available in the NOvA instantiation, including the central device database, java Open Access Clients, erlang front-ends, application consoles, synoptic displays, data logging, and state notifications. Acnet at NOvA is used for power-supply control, monitoring position and strain gauges, environmental control, PLC supervision, relay rack monitoring, and interacting with Epics PVs instrumenting the detector's avalanche photo-diodes. We discuss the challenges of maintaining a control system in a remote location, synchronizing updates between the instances, and improvements made to Acnet as a result of our NOvA experience.  
poster icon Poster TUPPC070 [0.876 MB]