Use Case:  Align Beam Launchers & Combiners

Description:  Perform the iterative alignment of the Beam Launchers & Combiners with the stellar beam

Role(s)/Actor(s): 
Primary: PRIMA Metrology Control System
Secondary: Alignment Unit

Priority: Major

Performance: up to a few minutes (TBC)

Frequency: At any time

Preconditions: 

• Beam Alignment sub-system is ONLINE

Basic Course: 

• Send command ALIGN to the Beam Alignment sub-system
• Beam Alignment sub-system schedules the alignment process until the convergence criteria are met or max time/iteration reached:
  • Read IR Detector
  • Compute the offsets
  • Check convergence criteria
  • Subflow: Move AMBER or MIDI Metrology Alignment Motors
  • Subflow: Move FSU-A Alignment Motors
  • Subflow: Move FSU-B Alignment Motors
• Beam Alignment sub-system sends OK/ERROR reply with the alignment quality

Subflow: Move AMBER or MIDI Metrology Alignment Motors

• Move Motors

Subflow: Move FSU-A Alignment Motors

• Send command to FSU-A Control Software

Subflow: Move FSU-B Alignment Motors

• Send command to FSU-B Control Software

Alternate Course: 

• Send command EALIGN to the Beam Alignment sub-system
• Beam Alignment sub-system terminates the alignment process
• Beam Alignment sub-system sends OK/ERROR reply with the alignment quality

Postconditions: 

• Beam Launchers & Combiners aligned with the stellar beam within the given criteria or time limit

Issues to be Determined or Resolved:  Convergence criteria, maximum duration, number of iterations

Notes:

Last modified: Fri Feb 21 13:05:26 MET 2003