Use Case:  Center Object

Description:  Centers the target object on the telescope field using the Autoguiding error vector evaluation fuctions

Role(s)/Actor(s): 
Primary: Operator,Maintenance
Secondary: FAS/FSS sub-system, tracking axes

Priority: Desirable

Performance: 30 seconds

Frequency: At preset time

Package Assignment:  Auto Guiding.

Preconditions: 

• ATCS is ONLINE Tracking
• AG / FS are Idle
• FAS is ONLINE
• Coude Beam Switching device allows light path to FAS/FSS

  Interface:  IfBeamSwitchingDevice.Encoder.ReadoutPosition

• a Guide Reference Point is defined

Basic Course: 

• Send command CNTOBJto start Object Centering
  Exception course: Command failed
• ATCS Sets Guide Reference Point to center field.
  Exception Course: Command failed
  
• ATCS performs Center Guide Star automatic centering with the FAS/FSS. Since the guide reference point is set to center field, the target is used in place of the guide star.
  Exception Course: Command failed
  
• ATCS Sets Guide Reference Point to original value.
  Exception Course: Command failed
  
• ATCS returns OK reply

Exception Course: Command failed

• ATCS returns ERROR reply

Postconditions: 

• Target object is centered in the field of view

Issues to be Determined or Resolved: 

Notes:

Last modified: Thu Dec 20 15:21:58 UTC 2001