A TASTE OF CAFE

CAFE (Channel Access interFacE) is a new C++ library that provides a multifaceted interface to the latest CA functions released with EPICS version 3.14. Functionality for both synchronous and asynchronous interactions has been implemented for individual, groups and collections of related channels. An abstract layer that addresses requirements dictated by beam dynamics applications has also been provided. An XML-based configuration mechanism provides a convenient framework for users to define and initialize CAFE objects, e.g. for data analysis and/or visualization. Rules to flag members of a group or collection of CAFE objects, effectively modify a transaction to a selected subset, thereby allowing users to readily adapt to changes in a system during operation. CAFE is intended for use in C++ frameworks such as Qt and presents itself as a candidate for Event Processing Agents (EPAs) that, for example, capture machine physics data for inter-shot analysis at the SwissFEL. In this respect, the role of CAFE in aggregating low-level hardware events to produce events that supply summarized data to a Data Distribution Service (DDS), is demonstrated.