Commissioning of the SLS digital BPM system

During the commissioning of the Swiss Light Source (SLS) first operational experience has been gathered with the newly developed digital beam position monitor (DBPM) system. The DBPM performance could be characterized in all available operation modes, which are: single turn, turn-by-turn, closed orbit and tune. All modes can be selected independently for each sector of the booster and storage ring through the EPICS-based SLS control system by simple re-programming of the digital processing chain. Laboratory measurements as well as measurements on the SLS accelerators will be presented, offering insights in the operational experience and the performance of the DBPM system. In addition, a monitoring system (POMS) for the transverse mechanical positions of each BPM block in reference to the adjacent quadrupole magnets has been installed and commissioned. First results will be presented, showing a horizontal and vertical movement of the BPM blocks as a function of beam current (heat load on the vacuum chamber) in the SLS storage ring.