  The Swiss Light Source (SLS) has in the order of 500 magnet power supplies
(PS) installed, ranging from from 3 A/20 V four-quadrant PS to a 950 A/1000 V
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
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 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.
