= VIS Operations Manual - Type A Suspension =

[[attachment:Type-A tower.png|{{attachment:Type-A tower.png||width = 600}}]]<<BR>>

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<<TableOfContents()>>
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== Aligning the Type-A suspension when pumping the chambers ==

=== Torsion (yaw) alignment ===

 1. '''Prep for monitor channels.'''
   * Monitor `K1:VIS-ETMY_BF_DAMP_Y_INMON` using `dataviewer` or `StripTool`
   * Also, it is always a good idea to monitor the test mass optical lever whose channels names are something like `K1:VIS-ETMY_TM_OPLEV_TILT_YAW_OUTPUT`.
   * When looking at the optical lever, make sure that the sum is close to 50,000 counts. If smaller, this likely means that the beam fell off from the QPD.
   * For lazy persons, there is a template for `StripTool`:
   {{{
   StripTool /users/kiwamu/templates/striptool/ETMY_oplevs.stp
}}}
 1. '''Rotate the BF (bottom filter) using the pico motor'''
   * From `sitemap`, go to `PICO`. This will open the pico motor summary window.
   * In the pico motor window, click on `ETMY` and select `Payload Yaw` in the pull down tab.
   * This will open up a small pico motor window.
   * Type in the appropriate number in the `STEP` form.
   * Roughly speaking, 8 steps give a yaw rotation of 1 urad.
   * Click on either `FWD` or `REV`.
   * `FRD` rotates the BF and the payload in clockwise as seen from the top. `Rev` does a counter-clock wise rotation.
 1. (!) '''Make sure that the suspension responded by looking at the monitor channels.'''
 1. /!\ '''If the suspension doesn't move, restart the pico motor script.'''
   First, log in to the script machine by running
   {{{
   ssh k1script -l controls
   }}}
   Then check whether the script is still running or not by typing
   {{{
   ps -elf | grep ETMY
   }}}
   If a running process exists, kill it in order to avoid duplicated processes.
   {{{
    kill aaaa
    }}}
   where `aaaa` is the process ID number. No action is required if there is no running process.
   Restart the script by
   {{{
     pico_start ETMY
   }}}
 1. /!\ /!\ '''If the `pico_start` is unable to restart the process and leaves error messages, try sending a `ping` to the IP address that is shown in the error message.'''
   If the pico motor driver doesn't respond to the `ping` command. Then someone needs to go to the 2nd floor of the EY station and physically switch off and on the pico motor driver. The pico motor driver resides in the clean room of the second floor. It is a black box with a white label on it saying `EYV` or something similar.

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=== Pitch alignment  ===
 1. '''If the amount of misalignment is small i.e., the optical lever still receives the light, one can use the marionette stage.'''
   Use the test filter bank in the cryogenic payload medm screen and type in offset in the `K1:VIS-ETMY_MN_TEST_Y_OFFSET`.
 1. '''Use the moving mass which is on the payload marionette stage.'''
   This requires a dedicated Windows machine for now. Call an expert for it.