Use Case:  Set Coudé Beam Switching Device

Description:  Set Coudé Beam switching device to required position
This action is dedicated to optical alignment and maintenance procedures and during normal operation.
The allowed positions are:

• Mirror (Coudé beam to FAS only)
• Beam Splitter (splits the Coudé beam to FAS and FSS)
• Free Hole (Coudé beam to FSS only)
• Light Stop (Coudé beam does not reach the sensors)
• FSS Pupil Viewer (enables to view the image of the pupil on the FSS APD)

Role(s)/Actor(s): 
Primary: Operator, Maintenance
Secondary: Coudé Beam switching device

Priority: Major

Performance: TBD

Frequency: Asynchrously, typ. before and after alignment procedures

Package Assignment:  Coudé Focus Device.

Preconditions: 

• Coudé Beam switching device is ONLINE

Basic Course: 

• Send command SETBEAM <STOP|MIRROR|HOLE|SPLIT> to set the Coudé Beam switching device to the given position
  Exception Course: Command failed
• ATCS sets the Coudé Beam switching device to the given position

  Interface:  IfBeamSwitchingDevice.Motor

  Exception Course: Command failed
• ATCS returns OK reply.

Exception Course: Command failed

• ATCS returns ERROR reply.

Postconditions: 

• Coudé Beam switching device at given position

Issues to be Determined or Resolved:  Will it be done a any time during observation or at start or certain steps? We might think of a combination of FSS ND Filter + Beam Splitter or Free Hole

Notes:The command GETBEAM returns the name of the Coudé Beam Switching Device position.

Last modified: Fri Nov 23 11:53:47 UTC 2001