Use Case:  Start Chopping

Description:  Starts Chopping with mirror M6

Role(s)/Actor(s): 
Primary: VLTICS-ISS, Maintenance
Secondary: TRS

Priority:  Major

Performance:  1 second

Frequency:  At any time

Package Assignment:  Chopping.

Preconditions: 

• ATCS is ONLINE
• Chopping configuration parameters are valid and available

Basic Course: 

• Send command STRTCHP <absTime> to start chopping at given absolute UTC
  Exception course: Command failed
• ATCS loads the chopping parameters
  
• ATCS launches a TRS timer starting at the given time <absTime> with the given period for the Chopping loop
  Exception Course: Command failed
• ATCS configures Guiding (if applicable) to support guiding while chopping
  Exception course: Command failed
• ATCS sets Chopping Phase to ON
• ATCS returns OK reply and UTC of next ON phase

Exception Course: Command failed

• ATCS returns ERROR reply

Postconditions: 

• Chopping active
• Guiding (if applicable) takes chopping into account

Issues to be Determined or Resolved: 

Notes:...

Last modified: Thu Jun 28 13:08:40 UTC 2001