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
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.
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.
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.
Last modified 02/15/99