The Advanced Photon Source
a U.S. Department of Energy Office of Science User Facility

Lesson Module A-16: Turning the Key - pg 3

The Personnel Safety System (PSS) monitors the state of variables relevant to personnel safety (i.e. station door status, shutter status, etc.) When PSS detects that a variable is not in the correct state, a fault occurs, and the Front End shutter permit is removed. Floor Coordinators and MCR Operators are allowed to reset particular faults under certain conditions.

We currently have two generations of PSS operating at various beamlines{each generation has two (2) systems each}: Generation 1 Systems(G1), Generation 1 SystemsUpgraded(G1U), Generation 3 Systems(G3) and Generation 3 Systems upgraded(G3U).
The G1 and G3 systems use terminology indicating Minor, Serious, or Major Faults. The G1U and G3U Systems use terminology indicating Trips, Faults or Warnings for upset conditions. As of January 2013, the following beamlines have G1U or G3USystems: 2BM, 3ID, 5BM, 5ID, 6BM, 8BM, 9BM, 10BM, 10ID, 12BM, 12ID, 13ID, 14ID, 15ID, 17BM, 17ID,20BM, 22BM, 22ID, 23BM{G3U}, 23ID, 24BM{G3U}, 24ID and 29ID{G3U}
PSS Minor Fault or Trip

Some of the most common faults that occur are PSS Chain A minor faults (on G1and G3 PSS) or trips (on G1U or G3U PSS). They include door faults and water flow faults. FC's and MCR operators may reset these faults up to three times per shift prior to notifying a SI on-call engineer.

Please take time to review the following procedure: PSS Minor Fault Reset Procedure
PSS Serious Fault or Fault

Other less common faults that occur are serious faults (on G1 or G3 PSS) or faults (on G1U or G3U PSS). A serious fault is caused by shutter or stop position switch misoperation or remote I/O (input/output) communication failures.These faults will remove ALL shutter (Front End and Integral) shutter permits.Under this failure mode, circumstances may exist that could lead to tripping stored beam so caution should be exercised.To reset this fault, the following Standing Order shall be exercised: PSS Serious Fault Reset

Note: Floor Coordinators may only reset shutter or stop position switch misoperation serious faults one time prior to calling a SI on-call engineer. MCR operators are not trained to reset serious faults at this time.
PSS Major Fault

A PSS major fault (on G1 or G3 PSS only) is one that will dump the entire storage ring. Floor Coordinators and MCR Operators are not permitted to reset major faults. If a major fault should occur, Floor Coordinators must make contacts with SI on-call personnel to help with the diagnosis and troubleshooting of the problem.
PSS Warning

A PSS warning (on G1U or G3U PSS only) is issued by the system for potential future failures on a beamline's PSS. Warnings do not inhibit beam to a beamline, and require no reset.