Use Case:  Stop Field Stabilization

Description:  Stop Field Stabilization As soon as Field Stabilization is stopped, M6 goes directly to center position. The center position is defined as (0,0) plus the offset value set in the SETUP database branch.

Role(s)/Actor(s): 
Primary: Operator/Maintenance
Secondary: FSS, TRS

Priority: Major

Performance: A couple of seconds

Frequency: Before a preset when field stabilization was active, or at any time manually or when FS conditions are not met.

Package Assignment:  Field Stabilization.

Preconditions: 

• FSS sub-system is ONLINE

Basic Course: 

• Send command STOPAG to stop the Field Stabilization
  Exception Course: Command failed
• ATCS Disables Field Stabilisation
  Exception Course: Command failed
• ATCS cancels the TRS timer for the Field Stabilization Loop
  Exception Course: Command failed
• ATCS returns OK reply

Exception Course: Command failed

• ATCS returns ERROR reply

Postconditions: 

• FS is idle

Issues to be Determined or Resolved: 

Notes: The STOPAG command is used to stop both Auto Guiding and Field Stabilization, which ever of the two is active when the command is active.
No action occurs if none is active.
See Stop Autoguiding. The two Use Cases could/should be merged in a single one taking care os the different possibilities.
During Field Stabilization, the FAS is always active in fill screen mode, so it is not necessary to explicitely switch it on as a step of the Use Case.

Last modified: Thu Dec 20 15:29:12 UTC 2001