The Flange for Controls System to Internet Applications
A. C.Starritt, C.A.Myers, R.I.Farnsworth* (ASCo)
A technique for delivering process variables to web enabled applications has been collaboratively developed by the Australian Synchrotron controls team and a local e-research initiative team called VERSI at the Australian Synchrotron. EPICS process variables are collated by a program called the "Flange" which acts as a gateway and passes the value, selected metadata such as enumeration type, connection state, update times etc range to a mySQL database which contains short term historical records which then allows standard web based applications, in our case AJAX (Asynchronous JavaScript and XML)) web applications. The flange supports a Historical Backfill from the Control systems archiver, throttling (i.e. Minimum updates and dead banding) and finally image processing (useful for taking arrays and waveforms) and converting to standard image formats stored in the SQL database.