Open B-shutter (P6-50 Safety Shutter)

Warning

STATUS: STUB. Placeholder for the procedure that satisfies the precondition b_shutter_open of Detector Z-rail alignment to the beam (detector_z_rail_alignment). To be fleshed out as the procedure is implemented.

Name

open_b_shutter

Source

Not yet implemented. Future location: procedures/open_b_shutter.py in the 2bm-procedures repository.

Devices

Beamline components: P6-50 Safety Shutter (B-shutter) — S02BM-PSS:SBS. Open command OpenEPICSC; close command CloseEPICSC; status readback S02BM-PSS:SBS:BeamBlockingM.

Preconditions

Enable beamline for beam (enable_beamline) — PSS must permit the open.

Parameters

(none)

Steps

caput S02BM-PSS:SBS:OpenEPICSC 1.
Wait for S02BM-PSS:SBS:BeamBlockingM to read OFF (STATE 0; inverted enum — OFF means NOT blocking → shutter OPEN). See Beamline components for the semantic note.

Postconditions

Satisfies:: b_shutter_open
Predicate:: S02BM-PSS:SBS:BeamBlockingM == 0 (i.e. OFF).

Failure modes

BeamBlockingM does not transition to OFF within the timeout — PSS permit not granted, hardware fault, or BLEPS Fault latched. Verify upstream interlocks; do not retry blindly.