Signal Archiving and Retrieval: Essential Long Term Performance Tuning Tool

The first two years of user service of the third generation light source BESSY II emphasized the importance of a reliable, comprehensive and dense logging of a few thousand setpoints, readbacks, status and alarm values. Today data from sources with various characteristics residing in different protected networks are centrally collected and retrievable via an uncomplex CGI program to any desktop system on the site. Data post-processing tools cover Windows applications, IDL, SDDS and custom programs matching users skills and preferences. In this paper illustrative sample data explorations are described that underline the importance of the logging system for operations as well as for the understanding of singular events or long term drifts. Serious shortcomings of the present installation and focus of further development are described.