SDSS Interlock System Work
January 18-21, 1999

Sloan Digital Sky Survey Technical Note 19990118

Glenn Federwitz and Angela Prosapio, Fermi National Accelerator Laboratory Batavia, IL 60510 USA

Rotator Read Head Cables

The four cables for the rotator read-heads were installed and terminated to the top of the rack. One read head went to the fiducial board in the back of the rack. The other three went to the MEI board channels 3,4,5. On the PSS, the cables were connected to the associated interpolator box which was mounted inside the PSS. 1-meter long Heidenhain cables were connected to the other side of the interpolator and brought through a slot under the rotator wrap guard. The read-heads can now be installed at any time, connected to the 1-meter cables, and ty-wrapped down.

Windbaffle Manual Control Box Cable

The cable on the windbaffle manual control box was replaced with a longer cable.

Altitude Fiducial Connector

Found a bad bulkhead connector on the top of the controls rack and replaced it.  The cable from the altitude fiducial head interpolator connected to this bulkhead.

Ribbon Hose for Astigmatism Control Box

Ran (2) 8-hose ribbon hoses for Jim Gunn from the south fork of the telescope to the PSS.

Telescope Counterweight & Rotator Motor Cables

Cables for the east-side telescope counterweights, the altitude clinometer, and rotator motor power had to be moved.  New holes were drilled and the cables re-terminated so the new rotator motor can now be installed.

Rotator Motor

The new motor has been temporarily terminated to a Burndy connector with a 750-ohm resistor and varistors across the leads.

Rotator Limit Boxes

The new rotator limit switch housings that Steve Bastian built for the 270-degree CW and CCW limits have been wired and are ready for installation.  The old switch housings had to be replaced since they would not fit into the available space on the new rotator.

Altitude Hard Limit Switch

A new altitude limit switch box has been wired and installed on the telescope.  The new box includes a fifth switch that was added to provide a 19-degree hard limit;  this limit will stop telescope-up motion at 19 degrees when the telescope is being moved within the building.  This new switch was added to the splitter chassis on Slot 9, Channel 6.  It was also added to the low-level interlock logic.  While the switch is in place, the switch actuator is not, therefore this limit is not yet functional.  Steve Bastian has been informed of the need for the actuator and will make and install one when time permits.

Altitude Fiducial Interrupt

We verified that the 200-ns interrupt pulse from Claudio Rivetta's altitude fiducial board was getting to the MCP.

Glen-Tek Amplifiers

The rotator amplifier analog board was modified to match the analog modules of the four altitude and azimuth motor amplifiers, since the new rotator motor is now the same motor as used on the azimuth and altitude drives.   The analog module from the spare rotator amplifier was also modified.

Rotator Junction Box Cabling

The rotator junction box power & serial-link cables were temporarily terminated to the bulkhead Burndy connectors that will go on the rotator wrap header plate in the PSS. 15-foot long power & serial cables were made so they could be installed in the wrap when French installs the wrap. The rotator junction box had two 4-foot pig-tails temporarily terminated for the header plate on the rotator. They will be connected to the plate when the plate is installed.

Barcode Reader Serial Cabling

The TERMINAL ouputs on the altitude and azimuth bar code interface boxes were connected to the MCP through a 50-pin ribbon cable break-out board.  Charlie Briegel will install an RS-232 IP board into the VME crate so the MCP can communicate with both bar code readers.  Until the RS-232 board is installed, only one scanning head can be accessed at a time.

Comments regarding this trip report should be addressed to Glenn Federwitz at (630) 840-4836 or Angela Prosapio at (630) 840-3013.

Last modified 02/15/99