The Australian Synchrotron safety system incorporates two Pilz Programmable Safety Systems (PSS 3000) or safety PLCs, along with a Pilz PMIvisu touch screen machine interface. It incorporates 68 emergency stop buttons, keyed interlocks, Fortress gates, video cameras, and even an intercom – all used to control personnel access into and out of the six controlled areas, and to provide immediate isolation of energized equipment in an emergency. All the safety and operations data is fed into an archive system so that in the unlikely event of an incident, investigators could effectively retrace the steps of synchrotron staff.