The Metrology Light Source (MLS) is in user operation since April 2008. This versatile facility has to work at energies ranging from 105 MeV up to 630 MeV, operating currents from a single electron up to 200 mA and different values for the momentum compaction factor according to the user demands that vary even on very short notice. A software system has been developed to control and coordinate the broad manifold of machine states. Design goal of the software was to keep and transfer machine and control system within well-defined and consistent states. It should minimize errors due to inadvertences and avoid mistakes when following complex command sequences. The software is modelled as a finite state machine. Actions are configured and triggered by a few high level commands. This paper describes program functionalities and interfaces. Experiences with `automated operation' using this indispensable operator tool for a reliable setting up of a very sensitive machine are reported.