Background

The MAGIQ guiders used on LRIS have two amplifiers which are used to read out images. If the bias levels on these amplifiers are discrepant then the resulting images output from the guider can be difficult to view. Follow the steps below to return the bias levels to their correct value.

Procedure

Start MAGIQ GUI

  1. Log into k1server: 
    	ssh k1obs@k1server
  2. Launch DSGUI: 
    	dcsgui
  3. On DCSGUI, click on DCS > MAGIQ to bring up the MAGIQ Operations Menu.
  4. On MAGIQ Operations Menu, click on Start OA GUI to bring up the OA GUI.

Start Saving Images

  1. On the Camera and Guider Control tab, click on NULL and select either lrisSlit or lrisOffset, then click on Expose to begin exposing.
  2. On the Extended Camera Controls tab, click on Save next N images to save an image.

Adjust Bias Levels

  1. On the top menu bar, click on Camera > Diagnostics to bring up the Diagnostic panel.
  2. Click Load Defaults to ensure that default values are loaded.
  3. Enter new values for Ch 1 Offset and/or Ch 2 Offset and click the S button to change the setting. Note: you should only make incremental, preferably by 1 or 2 units.
  4. Acquire a new image and check bias level.
  5. Iterate previous 2 steps until bias levels converge at the desired level.

Save Settings

Follow these steps to make new LRIS guider offset values permanent:
  1. Log into magiq server via 
    	ssh magiq@k1-magiq-server
  2. Change to directory: 
    	cd /kroot/magiq/default/configData/KECK1/Cameras/
  3. Hand-edit the appropriate file:
  4. Modify the following lines: 
        <Bias index="0" value="326"/>
    <Bias index="1" value="294"/>