Install controller

 The installation of the CS-100 Fabry-Perot controller is substantially different between the two Palomar telescopes:

• 60-inch
  The controller is usually placed on a rolling cart beneath the telescope. The long blue RS-232 extension cord provided with the Fabry-Perot equipment should be used to fasten the controller (Figure 9h) to the RS-232 line coming from the base of the telescope pier . This will connect the controller to port TTA3: on the Microvax in the second-floor computer room (OSCAR). The power cord for the controller (Figure 9g) should be plugged into the power strip also found at the base of the pier. You will probably want to use a small extension cord as well, in case the controller cart needs to be moved substantially during the course of the night. Please make sure that the controller is turned off before plugging in the power. (Note: Some experiments have detected noise in the Fabry-Perot system which appears to vary with the choice of outlet in the plug bar on the telescope pier. If you seem to be having problems with noise, try connecting to a different socket in the plug bar; the socket on the North end of the bar has been found to work well.)

• 200-inch
  At the 200-inch telescope, the CS-100 controller arrangement is much simpler: the controller is mounted into a standard electronics rack, which is then fastened to the side of the Cassegrain cage. The Palomar crew will provide the rack.

  First, the outer case of the controller must be removed, in order to mount it in the rack. You need remove only four screws on the front of the controller, two at either end. The controller should then slide forward, out from within the case. Since this removes the protective covering from most of the controller's internals, be careful in the following steps. Mount the controller in the rack using the now-vacant holes in the front panel of the controller and four of the screws provided with the rack. The controller only fastens to the rack in front, as the rack is much deeper than the controller. You may want to attach the cables to the back of the controller at this time as well, before the rack is mounted on the telescope.

  Once the Palomar staff has fastened the rack to the telescope, the cables should then be configured. The power cable (Figure 9g) is connected to one of the power strips in the Cassegrain cage. Please make sure that the controller is turned off before plugging in the power. The RS-232 cable is connected to the controlling computer using a pair of short-haul modems, which may be found in a small box with the Fabry-Perot cables. These modems translate the RS-232 signal to/from one of the analog BNC control lines running between the patch panels in the Cassegrain cage and the mezzanine-level computer room. One of the short-haul modems is placed directly on the RS-232 connector on the CS-100 Fabry-Perot controller (Figure 9h). A short coax cable is then used to connect this modem to the patch panel above the controller rack, on the west side of the Cassegrain cage. Consult the Palomar staff to determine which BNC control line should be used. The other short-haul modem should be attached to port TXA7: on the back of the Microvax in the computer room on the mezzanine level (SAM). This modem is connected to the appropriate BNC port on the patch panel in the computer room, using another coax cable. (Coax cables can be found hanging on the wall in the astronomer's workshop, adjoining the main observing room.) Feel free to consult the Palomar staff for help installing the modems, to ensure that they are attached to the correct computer port and to the proper BNC line.

  

Figure 8: A schematic of the front side of the CS-100 Fabry-Perot etalon controller, illustrating the location of various dials and meters.

  

Figure 9: A schematic of the back side of the CS-100 Fabry-Perot etalon controller, illustrating the location of various cable connectors.