Collaboration Case:  Offset Alpha/Delta

Description:  Offset the Altitude and/or Azimuth axes of the given (alpha,delta) step.
The offset step is relative to the current position of the telescope (i.e. consecutive offset steps are accumulated).

Role(s)/Actor(s): 
Secondary: Alt/Az Axis, XY-table, FAS-window, Interaction matrix

Performance: up to 1.5 deg/sec in Alt and 2 deg/sec

Frequency: Asynchronous up to 10 Hz

Package Assignment:  Tracking.

Preconditions: 

• ATCS is ONLINE Tracking

Basic Course: 

• Send offset (alpha/delta) in arcsec
  Exception Course: Command failed
• ATCS sends the new offsets to Alt/Az axes and the Probe

  Interface:  IfAltDrive IfAzDrive IfFssTranslationStage IfFas IfInteractionMatrix

  Exception Course: Command failed
• ATCS returns OK reply

Exception Course: Command failed

• ATCS returns ERROR reply
  Postcondition: ATCS state ONLINE TRACKING

Postconditions: 

• Alt/Az axis are offset of the (alpha,delta) amount

Issues to be Determined or Resolved: 

Notes:

Last modified: Thu Jun 28 14:00:01 UTC 2001