Use Case:  ATCS Shutdown

Description:  This is the normal operation before a system complete or partial power-down or reboot.
Each required subsystem is brought from state STANDBY to state OFF. A failure will leave the ATCS in state OFF substate ERROR.

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

Priority: Desirable. The sequence can always be performed step by step by the operator.

Performance: 10 minutes

Frequency: Typically, before relocation procedure.

Package Assignment:  Mode Switching.

Preconditions: 

• ATCS is in state STANDBY

Basic Course: 

• Send command SHDOWN to Shutdown ATCS
  Exception Course: Command failed
• ATCS sends STOP command and puts in OFF state all required and not ignored subsystems

  by using Standard Command

  Exception Course: Command failed
  Postcondition: all required and not ignored subsystems are in OFF state
• ATCS global system state update
  Postcondition: ATCS in state OFF, substate IDLE
• ATCS sends final OK reply

Exception Course: Command failed

• ATCS global system state update
  Postcondition: ATCS in state OFF, substate ERROR
• ATCS sends final ERROR reply

Postconditions: 

• ATCS is in state OFF substate IDLE
• All required and not ignored ATS subsystems are in state OFF
• Control loops are disabled and brakes engaged

  Interface:  IfAltDrive,  IfAzDrive

• ATCS ready to accept Mode Switching commands

Issues to be Determined or Resolved: 

Notes:

Last modified: Thu Jun 28 13:32:57 UTC 2001