= IO active Tip Tilt suspensions =

The two input steering mirrors and two output steering mirrors are suspended from aLIGO tip-tilt mirror assemblies:

 * [[https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?.submit=Number&docid=D1001396|aLIGO Tip-Tilt Mirror Assembly (D1001396)]]

They have OSEMs (BOSEMS), but we're only using the coil driver part (no shadow sensing).

 * [[http://dx.doi.org/10.1063/1.3669532|Tip-tilt mirror suspension: Beam steering for advanced laser interferometer gravitational wave observatory sensing and control signals (Rev. Sci. Instrum.)]]

== Wiring ==

Below is a wiring/electronics overview diagram.  We are using iLIGO SOS coil driver electronics, controlled by the aLIGO RTS.

{{attachment:40m-tt-wiring.svg}}

 * [[https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?.submit=Number&docid=D000316|Eurocrate SOS dewhite/anti-image boards (D000316)]]
 * [[https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?.submit=Number&docid=D010001|Eurocrate SOS coil driver boards (D010001)]]
 * [[https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=8973&version=10|in-vacuum "quadapus" cables (D1000234-v10)]]

Notes:

 * The cables connecting the DAC interface board (D080303) and the SOS DW/AI boards (D000316) is a '''''custom''''' ribbon cable that goes from the 40-pin IDC connectors on the DAC interface to the 66-pin IDC connectors on the Eurocrate backplane.

=== In-vac wiring ===

relevant pictures:

 * BSC table, from north, input PZT2 detail: [[https://picasaweb.google.com/foteee/BSchamber_general_2July2012#5760738286971644386|1]], [[https://picasaweb.google.com/foteee/InVacWork4Aug2011#5637286023354525762|2]]
   * '''''Do we have 3 available 25-pin connectors on BSC table??'''''
 * IOO table, from west, through AC, input PZT1 detail: [[https://picasaweb.google.com/foteee/InVacWorkNov232010#5544001991913055442|1]], [[https://picasaweb.google.com/foteee/InVacWorkNov232010#5544002001413250658|2]]
   * '''''It looks like we have (or will have) 1 available 25-pin connector on IOO, which is all we need!''''' 
 * OMC table, from east, through AC, output PZT1(?) detail: [[https://picasaweb.google.com/foteee/InVacWork4Aug2011#5637288817950887378|1]], [[https://picasaweb.google.com/foteee/InVacWork4Aug2011#5637288262639879746|2]]
   * '''''unclear what is available here'''''