Seeing Limited Operation of the LBT Adaptive Secondaries

This guide is describes how to "Set" the Adaptive Secondary (AdSec) at beginning of an observing night and how to "Rest" it at the end. It's audience is non-AO people such as the Telescope Operators and Instrument Specialists. These instructions only describe how to Set and Rest the AdSec if and only if the AO system is in a power-on state. This means the required processes are running on the AdSec computer (adsecsx or adsecdx) and that the Adaptive Secondary unit is powered up.

If a problem arises, as several such problem are described below, call the AO Support Person listed in the Science Support Schedule Calendar. The AO Support Person's cell phone number can be found in the LBTO Phone Directory.

Changing Adaptive Secondary States

Once the AdSec is in "Set" state, the Adaptive Secondary is operating with about a 60 micro gap between the thin shell and the solid reference body. The front reflective surface is then flatten to better than 100 nm rms wavefront error. The AdSec is then ready for Seeing Limited operation. When the Adaptive Secondary is not in use it should be "Rest"ed. This means the thin shell is pulled against the reference body with a gap of less than 30 microns.

In order to operate in Seeing Limited mode, the AOS subsystem of the TCS must be operating for the side of the telescope you wish to use. Check the TCSGUI to insure the AOSL or AOSR is running. If not, then Click the Start Button for the needed AOS side.

To check the state of the Adaptive Secondary, and change the state of the AdSec, Click the GUI Button for the AOS side that will be used.

"Rest" State GUI

The AOS GUI for an Adaptive Secondary that is powered up and in the "Rest" state is displayed below. The important items to look at have been circled and will be discussed.

• AOS GUI with the Adaptive Secondary in "Rest" Mode:
  

• Adaptive Secondary State:
  

This part of the AOS GUI shows the Adaptive Secondary is powered on (the "Off" button is available) and in a "Rest" or "Safe" state. The "Set" button is available. The Green bar under the "Safe" label displays that all the processed needed to "Set" the AdSec into Seeing Limited Mode are running. If this bar displays Red, then call the AO Support Person.

• AO Arbitrator Process State:
  

The label "Operate" informs us that the high level communication between the AOS and the AO Supervisor (which controls the Adaptive Secondary and Pyramid W-Unit) is running. If this label is "Not Operating" then call the AO Support Person. Note, if this label is "Not Operating" it means the AOS cannot send requests to the AO Supervisor to change the state of the Adaptive Secondary. However, if the bar below the Adaptive Secondary state ("Safe" or "Set") is Green, then the status of the AdSec displayed is correctly.

• Pyramid W-Unit State:
  

For Seeing Limited operation, the power to the Pyramid W-Unit should be off. If the status label reads "On", call the AO Support Person.

Flatten the Adaptive Secondary or change from "Rest"ed to "Set"

• Flattening the Adaptive:
  

To flatten the Adaptive Secondary, click the "Set" button. This flattening of the Shell will take about two minutes, and when completed the status label will change to "Set". Occasionally the AOS GUI reports that the command timed out. This usually is not true, the AOS did just not wait long enough. In this case, the Adaptive Secondary will in fact become "Set" and the AdSec status label will soon change to "Set". If the AOS GUI reports a different error, or the Adaptive Secondary does not finally report that it's "Set", call the AO Support Person.

"Set" State GUI

The AOS GUI for an Adaptive Secondary that is powered up and in the "Set" state, or ready for Seeing Limited Operation, is displayed below. The important items to look at have been circled and will be discussed.

• AOS GUI with the Adaptive Secondary in "Set" Mode:
  

This part of the AOS GUI shows the Adaptive Secondary is powered on (the "Off" button is available) and is "Set". The "Rest" button is available. The Green bar under the "Safe" label displays that all the processed needed to "Rest" the AdSec into Seeing Limited Mode are running. If this bar displays Red, then call the AO Support Person.

Rip (Rest In Peace) the Adaptive Secondary or change from "Set" to "Rest"

• Resting the Adaptive Secondary:
  

To rest the Adaptive Secondary, click the "Rest" button. This resting of the Shell will take about 10 seconds, and when completed the status label will change to "Safe". If the AOS GUI reports an error, or the Adaptive Secondary does not finally report a "Rest" state, call the AO Support Person.

-- DougMiller - 07 Sep 2011