Station control panels can have one or more types of buttons used to operate the panel. If a button is pressed on a station control panel to carry out an action not permitted by the PSS, an alarm will sound to say this action is not allowed. The action will not occur, and storage ring current will not be affected.

Shutter controllers are found on most beamline stations. A shutter controller can control the station it is on, a station(s) upstream, or a combination of the two. All shutters upstream (towards the beam source) of a station must be open in order to bring beam into that station.

To open a shutter:

• The user key (in possession of beamline personnel) must be placed, turned clockwise, and captured in the panel.
• A search-and-secure procedure (described shortly) must be performed.
• An APS Floor Coordinator must enable the beamline using the APS reset key. This key does not remain captured in the panel; it is kept in the possession of the Floor Coordinator.
• All of the station control panel's LEDs/indicators must be green.