Application of digital regulated Power Supplies for Magnet Control at the Swiss Light Source

The Swiss Light Source (SLS) has in the order of 500 magnet power supplies (PS) installed, ranging from from 3 A/20V four-quadrant PS to a 950 A/1000V two-quadrant 3 Hz PS. All magnet PS have a local digital controller for a digital regulation loop and a 5 MHz optical point-to-point link to the VME 1 level. The PS controller is running a pulse width/pulse repetition regulation scheme, optional with multiple slave regulation loops. Many internal regulation parameters and controller diagnostics are readable by the control system. Industry Pack modules with standard VME carrier cards are used as VME hardware interface with the high control density of eight links per VME card. The low level EPICS 2 interface is identical for all 500 magnet PS, including insertion devices. The digital PS have proven to be very stable and reliable during commissioning of the light source. All specifications were met for all PS. The advanced diagnostic for the magnet PS turned out to be very useful not only for the diagnostic of the PS but also to identify problems on the magnets.