Clock Correction Board

This board - also referred as CCB - is part of the DUMAND shore system. Each of the DUMAND strings underwater contains 26 optical modules (PMTs and calibration modules) operated by a string controller located in the string center. The string controller collects the optical data via a digital TDC (time-to-digital converter) which itself runs with a local clock and sends it to the shore station through optical fiber. On shore, the CCB receives the data and continuously synchronizes the clock information of the string with a master shore clock as a reference, e.g. UTC or GPS. It then provides the digitized optical data with corrected 40-bit time information to the trigger and data acquistion system.

For further information see E.Hazen's memo "DUMAND Clock Correction System", Boston University, March 17, 1994.

WORD documents (using Microsoft Word 6.0):

Block diagrams (gif-format or postscript):

CCB Schematics

The electronics of the CCB has been designed with ORCAD SDT V4.2 (schematics) and TANGO PCB V2.2 (layout) on a 486-based PC. For further questions please contact Hans via e-mail at berns@phys.washington.edu.

Programmable logic:

The PLD/PAL source files (*.tdl, written for the software package TANGO PLD) and Jedec files (*.jed) can be found here. The files ccb_*.* are the files for the etched PCB version and ccbp_*.* for the prototype version.

Test equipment software and source codes:

There are some files written in C to generate EPROM binary codes for the fast serial data test generator. The data generation is based on Monster Buffer data recorded earlier with the real string hardware at the Hawaii Dumand Center.

Test equipment schematics

last update: November 3, 1995