To develop and operate the control system effectively at the Thomas Jefferson National Accelerator Facility, users require the ability to diagnose its behavior not only in real-time, but also in retrospect. The new Jefferson Lab data logging system provides an acquisition and storage component capable of archiving enough data to provide suitable context for such analyses. In addition, it provides an extraction and presentation_facility which efficiently fulfills requests for both raw and processed data. This paper discusses several technologies and design methodologies which contribute to the system's overall utility. The Application Programming Interface (API) which developers use to access the data derives from a view of the storage system as a specialized relational database. An object-oriented and compartmental design contributes to its portability at several levels, and the use of CORBA facilitates interaction between distributed components in an industry-standard fashion.

This work supported by the US Department of Energy under contract DE-AC05-84ER40150.

Author: Christopher Larrieu

Submitted for ICALEPCS 2001, San Jose, CA, Nov. 27-30 2001

Updated April 25, 2001

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