EPICS Direction to Support Large Projects and Incorporate New Technology Leo R. Dalesio 09/21/99
Challenging New Projects Will Push EPICS Developments The Next Linear Collider is estimated to have over 1 million Process Variables and has chosen EPICS as the toolkit to use in the implementation. The manpower estimated to accomplish this job is 500 man-years. SNS is being developed at 5 different laboratories and needs to be integrated at Oak Ridge National Laboratory in 2005.
Current Issues for the EPICS Toolkit Productivity gains have been made by providing tools in place of programming, but further improvements are required to support very large projects and widely distributed projects. Data taken by the control system needs to be available to operators, developers, commissioners, experimenters, maintainers and even management to support efficient operation. New developments will overcome some limitations in the current version of the database and channel access protocol.
Productivity Gains Are Crucial in Today's Tight Schedule and Budget Environments The EPICS learning curve is steep. User’s manuals and training have been provided reduce this. New training courses are planned to train operators. Relational databases have proven very appropriate for configuring instrumentation. Graphical databases make complex logical relations easier to document and maintain. Allowing subsystems to be developed and integrated from Labview, Intellution, ActiveX, and IDL give application developers the ability to apply tools that they know how to use. Integration issues need to be carefully weighed. Graphical state machines are being developed for sequential control in addition to the use of commercial products like Control Shell.
Extensions Provide Data to All Desktops The channel access client has made it possible to access any EPICS Process Variable from Solaris, HPUX, LINUX, vxWorks, Windows 98, and Windows NT for years. The PV Gateway resolved the potential overloading of the primary control system, when hundreds of clients want to connect to PVs, by reducing multiple requests for a PV into a single request into the control system. Several beta releases of JAVA display managers are available for areas where performance is not an issue. Archive data is being made available through a web browser to allow access from all platforms.
Current Limitations that will be Removed The database will be changed to support online add, periodic monitors, and operation on operating systems other than vxWorks. Channel access modifications will support larger string lengths, larger array size, description of structured data, and a more efficient communication protocol. Support interlaced priorities in channel access and I/O control to allow multi- IOC control loops to specify a high priority. A new directory service will provide name resolution for an NLC size project while keeping the reliability of the current method.
The Collaboration Continues to Evolve User facilities and new projects continue to provide support to extend the EPICS tool-kit, investigate new technology, and take advantage of commercial products. A large user base provides good feedback on the best opportunities to improve EPICS. Three years ago the major problems discussed were complex installation, meager documentation, a steep learning curve and lack of higher level tools. The current complaints are: the learning curve and finding the documentation. Open source will provide an environment where all members are able to make contributions and control the direction of their installation. The EPICS collaboration continues to be a collection of cooperating laboratories that benefit from each others experience and developments.