New EPICS Channel Archiver based on MDSplus data system

The EPICS Channel Archiver is used to store data exported by EPICS I/O Controllers (IOCs). The Channel Archiver acts as a Channel Access Client (CAC) and stores recorded data, acquired via periodic scan or monitored, into indexed binary files. MDSplus is a data management system used in several Nuclear Fusion experiments to handle experimental and configuration data. A data access Application Programming Interface (API) for local and remote data access is available for several languages, namely C, C++, Fortran, Java, Python, MATLAB and H>;L, and a set of visualization tools is available for data browsing and display. The paper presents a new implementation of the EPICS Channel Archiver which uses MDSplus for data storage. In this way, it is possible to take advantage of the availability of the local and remote data access layers of MDSplus, widely used in the fusion community to handle large sets of data. A performance comparison between the original implementation and the new one is provided. In particular, the storage space requirements and the data access speed are considered.