Telescope Ephemeris Safety Function

Owned by Tim Williams
Last updated: Nov 28, 2023
2 min read

Indication

Active State

 

Safe State 1

 

Condition

The GIC calculated Sun position was not within 1.5 solar radii of the actual telescope position.

If this occurs while the light path was not blocked then:

  • M1 Cover is forced to close

  • Aperture Cover is forced to close

Operator Procedure

  1. Do not open the M1 Cover, if the aperture cover is open.

If both the M1 Cover and Aperture Cover are open at the same time, the telescope must be ‘on-sun’ or the light path safety function will activate forcing both covers to close.

Technician Procedure

  1. Ensure telescope safety encoders are communicating properly.

  2. Ensure telescope safety encoders have been properly homed. Follow this procedure.

The telescope safety encoders have to be re-homed after any loss of power or loss of communications.

Engineering Procedure

Disable Telescope Ephemeris safety function

Complete Job Hazard Analysis prior to disabling Telescope Ephemeris safety function.

  1. If necessary, disable Telescope Ephemeris safety function.

    1. press:

    2. indicator should change to: