Also within the database are subdirectories for the event history data with names of the form VA_000N where N is a number of the archive class from 0 to 5. Each of these directories contains files with names of the form AR_000N_YYYY.MM.DD-HH.MM.SS where again N is the archive class and YYYY.MM.DD-HH.MM.SS is the Greenwich mean date and time at which the file was generated. When a file is full of data, then a new one is generated. Old data is removed after a configurable number of files has been filled.The data can only be viewed from the event screen and trend history in the PVSS user interface.