The Sls Beamlines Data Acquisition and Control System

In the first phase four beamlines have been constructed at the Swiss Light Source (SLS): two for the surface science community, one for powder and surface diffraction and computed micro-tomography, and the last one for protein crystallography. All of them are equipped with insertion devices, which users want to treat as beamline components like a monochromator or experimental station. The beamline control systems are based on the same hardware and software technology as is the machine. This implies extensive use of Personal Computers running Linux RedHat 6.2 and VME systems (PowerPC). The advantage of this choice is a staightforward implementation of the insertion devices into the beamline and experiment framework. Although the experiment Application Program Interfaces differ from beamline to beamline, the standard software technology for linking all sub-systems is based on the Epics toolkit and Cdev. The diagnostic tools provided by this toolkit are being extensively used during the beamline commissioning. Finally we describe some examples of integrating dedicated 3rd party and commercial non Epics software products for experiment control into the beamline control system. Key elements in this domain are CORBA, Python and EPICS Portable Channel Access Server.