AB Controls | SL Controls | PS Controls | LHC-CP | ST Controls

Home
News
Architecture
Documents
Minutes
Technology
Industrial
Activities
The team
Development

Controls Middleware Project Introduction

    The controls Middleware (CMW) project provides a common software communication infrastructure for the CERN accelerator controls. This infrastructure is successively replacing existing heterogeneous software protocols and provides new facilities for the LHC era. In particular the project supports the Accelerator Device Model and device I/O services, the publish/subscribe paradigm synchronized with Accelerator Timing, and interoperability with industrial control systems.

   The first version of the major components has been produced in spring 2001. Currently the main activity is concentrated at delivering the final version of the components and completing the functionality, notably in the area of system administration, access control and tools. Please check the News for new developments and how CMW is used.

   The main CMW product is the RDA (Remote Device Access), which implements the Device Model. For Java clients Device client API has been defined, which extends RDA definition and provides unification between RDA and MOM. On the server side  the Server Framework provides support for timing-driven polling to facilitate construction of CMW servers. This is complemented by the OPC Gateway which allows to bridge any OPC server and therefore access industrially controlled devices from the CMW Device API. The existing PS and SL devices can be accessed via servers, which have been developed by the CMW project team. The communication is based on the RDA package, developed in the framework of CMW and all servers relay on the Server Framework. 

   In addition to this a commercial, JMS-compliant messaging system  has been selected and purchased. This system provides loosely-coupled message-based communication and the CMW project has defined the topic API, which allows use of the system in an easy way.

   Other components which have been developed by the CMW project are device naming service and the configuration service. The configuration service can be used in CMW servers and offers access to any ORACLE database, even from the LynxOS Front-Ends.

The CMW Device Explorer allows to browse and access CMW devices anywhere at CERN. 

To the history of the project development:

The controls Middleware project was originally launched by the PS/SL controls convergence project to provide modern software communication architecture and services required to operate the PS/SL accelerator complex. The project shall support the Object Oriented paradigm and in particular the Accelerator Device Model. Other important requirements are the support for the publish/subscribe paradigm and interconnection with industrial control systems.

   The project team started with the study of the Middleware technology which resulted in a workshop organized by project members in March 1999. The User Requirement Document (URD) which is a join submission from several members of PS, SL, LHC and ST divisions was published in August 1999. Based on the requirements and on the study of technology the project team has published the Whitepaper which describes the technological choices and the proposed architecture.

   During the workshop held by the LHC Controls Project, domains at CERN where there is need for Middleware have been identified. Since then, initiatives have been taken to include some of these domains in this Middleware project.