atcsucCheckStrapPupilip

Use Case: Check STRAP Pupil Alignment

Description: Check the alignment of the pupil image on the 4 APD's inside the STRAP unit.

Role(s)/Actor(s):
Primary: Operator, Maintenance, VLTI-ISS
Secondary: Nasmyth Beacon, M6, Coude Beam Switching Device, FSS, FAS

Priority: Desirable

Performance: A couple of seconds (30 to 60 seconds)

Frequency: Asynchronous, typ. once after relocation, or any time for maintenance/test purpose

Package Assignment: Optical Adjustments.

Preconditions:

Coude Beam switching device is switched On and ONLINE
Nasmyth Wheel and Nasmyth Beacon are ONLINE
M6 is ONLINE
FSS and FAS are ONLINE
ROS shutter is open

Basic Course: using Nasmyth Beacon

Send command STRPAL to check STRAP Pupil Alignment using Nasmyth Beacon
ATCS sets CBSD to "STRAP Pupil Viewer" position
ATCS centers M6
ATCS switches OFF STRAP head (gate to zero)
ATCS sends FSS Table to estimated (stored in DB) position of Nasmyth beacon image.

Alternate course

ATCS sets NDF to appropriate value for pupil viewing (TBD)
ATCS sets Nasmyth Beacon Intensity level for pupil viewing
ATCS switches ON Nasmyth Beacon
ATCS takes FAS exposure (with appropriate set-up for Pupil Viewing) and display image
ATCS switches OFF Nasmyth Beacon
ATCS sends final OK reply

Alternate Course: using Star light

Send command to check STRAP Pupil Alignment using star light
ATCS sets CBSD to "STRAP Pupil Viewer" position
ATCS performs telescope Preset to star coordinates (field stabilisation ON)
ATCS adjusts NDF if needed to take into account "STRAP Pupil Viewer" transmission (50%).
ATCS takes FAS exposure (with appropriate set-up for Pupil Viewing on star) and display image
ATCS sends final OK reply

Exception Course: Command failed

ATCS returns ERROR reply

Postconditions:

Image has been sent to display
Nasmyth Beacon is switched OFF
Entry in Log File has been created (parameters TBD)

Issues to be Determined or Resolved:

Notes:

Last modified: Thu Feb 28 10:47:02 UTC 2002