Use Case: Display Guide Detector Signals

Description:  The image of the Field Acquisition Sensor or of the Field Stabilization Sensor is read with the requested frequency and displayed. In the case of the Field Stabilization Sensor, no real image is available, but a proper representation (TBD) of the measured error vectors, guide star intensity and other statistical parameters related to the operation of the APD sensor will provide the same level of logical information. If autoguiding/field stabilization is not active, it is possible to switch ON/OFF the display dynamically. If autoguiding is active, this is not possible. In this case, the display shall be switched ON/OFF setting the proper SETUP keyword when starting Autoguiding. The FAS is normally always active and with the display switched on since all Autoguiding and Field Stabilization commands take care of properly switching ON the display of the Guide Detector Field. The display of the FSS image can be switched ON/OFF independently from the FAS, but with the same limitations.

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

Priority: Desirable

Performance: a few seconds

Frequency: Whenever requested

Package Assignment:  Auto Guiding.

Preconditions: 

• AG & FS are IDLE
• FAS sub-system is ONLINE
• FSS Strap is ONLINE
• Coude Beam Switching device allows light path to FAS and/or FSS Strap

  Interface:  IfBeamSwitchingDevice.Encoder.ReadoutPosition

Basic Course: Switch ON/OFF display while idle

• Send command to switch ON display with setup configuration for FAS or FSS
  Exception Course: Command failed
• ATCS Prepares FAS Setup with selected setup configuration in continuous loop and full frame mode
  Alternate Course: ATCS Prepares FSS Setup with selected setup configuration in continuous loop and no M6 correction
  Exception Course: Command failed
• ATCS Starts Field Acquisition
  Postcondition: FAS active : full frame + display
  Alternate Course: ATCS Starts FSS Acquisition
  Postcondition: FSS Strap is collecting data
  Exception Course: Command failed
• ATCS returns OK reply

Exception Course: Command failed

• ATCS returns ERROR reply

Postconditions: 

• FAS active full frame
• FSS Strap active
• FAS images and/or FFS Strap data are visualized

Issues to be Determined or Resolved: 

Notes:

The current implementation of the TCCD SW does not allow to switch ON/OFF on the fly, during an infinite loop of exposures, the display of images. The switching of display is linked to the Start/Stop commands.

The STRAP SW will provide a panel editor class implementing this display and usable in ATCS graphical user interfaces. The panel class will be defined by STRAP SW people.

Last modified: Thu Jun 28 13:03:37 UTC 2001