Major Element details

Hub Chassis

The chassis is a model 431B Technoland 4U steel chassis with six 5.25" and one 3.5" open drive bays, and one hidden 3.5" drive bay. It will accommodate most 14-slot backplanes. The front door is lockable and provides access to the drive bays. The status indicators and dust filters are also located behind the front door. This particular chassis model provides a Fault Detection Module (FDM) to monitor internal temperature, CPU fans and system fans. The FDM provides fault status indication at the front panel and an audible alarm when a fault is detected.

NOTE: At this time, the FDM is ONLY monitoring internal temperature and system fans. It is not monitoring the CPU fans or the DOM power supply fans.


ATX Power Supplies
These are 400 watt hot swappable power supplies. If one should fail there is an audible alarm (separate from the FDM above) as well as front panel indication. Some earlier chassis do not have the front panel indication.


System Fans
These are 4 - (92x92x25mm), 2800 rpm, 49 cfm, 12 VDC, 2.9 watt, ball bearing fans.

Front Sub-Panel
Behind the drop down front door are the drive bays and numerous recessed push buttons and a rocker switch. The rocker switch is used for reseting the FDM audio alarm. The larger push button near the bottom is for turning on the ATX power supplies. Just above the power on button are five recessed push buttons. These are for different resets in the system. The top button labeled, POWER BUZZER RESET is presently not hooked up. Just below the power buzzer reset is a recessed push button labeled, RESET 1. This button is the hard reset for the CPU. The other recessed push buttons, RESET 2, RESET 3 and RESET 4 have no function at this time.

DOM Power Supplies
Two Acopian model W48NT370 48V, 175 watt switching regulated power supplies in series to provide 96 VDC , one 0 to +48V, one 0 to -48V to power up to 60 DOM's. ( These power supplies have dual internal fans.

Power Supply Filter Card
Switching regulated power supplies are used because of their efficiency. Because of this, there is a need for filtering out the high-frequency noise inherent in these supplies. This is the purpose of the filter board. In the DOR Revision 1 card, there will be significant filtering added. It is likely that the filter card will either change or go away completely once DOR Rev 1 cards are installed. NEED PHOTO

A board to fan out GPS Master Clock signals to 8 DOR cards. Also has a 20 MHz Oscillator on-board to provide synchronous clock signal during test. NEED PHOTO

DOR card
The DESY-Zeuthen supplied DOM readout card. The initial version of the DOR card - Rev 0 - is being used at present and will be used through production testing of the 1st years deployment DOMs. There is a Revision 1 DOR card that is in the final stages of design and will soon enter fabrication. The Rev 1 version of the DOR card is planned to be deployed at the South Pole this season to read out our 1st 4 strings. However, it will not be available in sufficient quantity until the late summer or early fall and therefore will not show up at most collaborating institutions until the winter.

This page maintained by Martin Stoufer
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