Use Case:  Close Enclosure

Description:  Close Telescope Enclosure and Inflate Seals

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

Priority: Critical

Performance: 2 minutes

Frequency: Once per day at end of night. Or any time when meteo conditions require to close.

Package Assignment:  Enclosure Subsystem.

Preconditions: 

• Enclosure sub-system is ONLINE
• (AT in Lower Position) OR (Altitude axis < 20 degrees elevation)
• Key button in Remote

  Interface:  IfEnclosure.GlobalStatus.LocalStatus

Since this action is Critical, the preconditions must be checked again before proceeding.
If one of them is not satisfied, no recovery attempt due to potential danger of mechanical damage.
ATCS shall raise an alarm and return ERROR reply

Basic Course: 

• Send command CLOSE <BOTH|NORTH|SOUTH> [,<angle>] to close the enclosure shell(s) of the specified angle, defaulting to fully closed, for both, front or rear shell and inflate the seals (ObservationDome).
  Exception Course: Command failed
• ATCS checks preconditions again
  Since this action is Critical, the preconditions must be checked again before proceeding.
  If one of them is not satisfied, no recovery attempt due to potential danger of mechanical damage.
  Exception Course: Check failed
• ATCS sends the command to the Enclosure sub-system

  Interface:   IfEnclosure.Control.Close,  IfEnclosure.Control.CloseFront,  IfEnclosure.Control.CloseRear

  Exception Course: Command failed
  Postcondition: Enclosure shell(s) closed of the given angle
• ATCS returns OK reply

Exception Course: Check failed

• ATCS raises an alarm
• ATCS returns ERROR reply
  Postconditions: Enclosure is open

  Interface:   IfEnclosure.Control.OpenStatus,  IfEnclosure.Control.OpenFrontStatus,  IfEnclosure.Control.OpenRearStatus

Exception Course: Command failed

• ATCS raises an alarm
• ATCS returns ERROR reply
  Postconditions:
  Enclosure is not or partially closed
  Seals are not or partially inflated

Postconditions: 

• The enclosure is closed of the given angle.

  Interface:   IfEnclosure.Control.CloseStatus IfEnclosure.Control.CloseFrontStatus IfEnclosure.Control.CloseRearStatus

• The seals are inflated if fully closed.

  Interface:   IfEnclosure.Seals.SealsInflatedStatus

Issues to be Determined or Resolved: 

Notes:

Last modified: Wed Oct 30 17:16:30 UTC 2002