text: Complex systems, such as medical imaging systems including positron emission tomography (PET) systems, may include multiple subsystems, or modules, that if powered simultaneously can cause significant inrush current in the system power supply. Without sequencing such inrush currents may cause power fluctuations that may lead to the resetting of some of the modules.
  To avoid large inrush currents, power to system modules can be sequenced. For example, system modules can be sequenced according to their physical location by addressing an appropriate slot in a system backplane. However, such addressing is not always possible in systems without backplanes and with only a limited number of pins for configuration.