Work On COBRA Backend

Progress Report On COBRA Backend

This page tells you how we are getting on with production of the COBRA backend.

It will give you an idea of the extent of the work required, and how much is left to do.

Phase 1 of the project as agreed on Friday 19th April 2002 is to provide enough instruments by September 2002, to record a band 50MHz wide, split into bands of 5MHz, and sampled at quadrature baseband at a rate of 5MSPS. This will require 10 Sampler Boards, 10 LED Display Boards, 10 Interface Boards, 10 LO modules, and three backplane boards mounted into three chassis. In addition, there will be 20 passband filters, and 40 low-pass filters.

Phase 2 of the project will increase this capacity by a further six sets of sampler, interface, and LO modules. This will allow us to observe a band up to 80MHz.

Phase 2 of the project will depend on the success or otherwise of Phase 1. Also we are constantly looking at the available technology, in particular, ways of getting data onto the PCI bus. At the moment we are using Adlink boards (PCI-7300A) which use 16-bit, 33MHz technology. We are waiting for affordable 32-bit 66MHz technology, which will revolutionise our data capture methods.

I set up an experiment with two Samplers, which feed data into two Interface boards, and thence two Adlink PCI Boards. This allowed us to to run two systems in parallel so we could test the repeatability of the hardware. This also gives the scientists opportunity to test the scalability of their software.
On 25th June we successfully ran the experiment using two samplers in parallel. We observed B0329+54 using the 42ft telescope. The result was very encouraging. Nice clear pulse booming in. Visually, at least, it was very difficult to distinguish any variance between the two systems. A more in depth comparison will be made soon. This is quite a simple experiment, and does not implement any scalability software. We just wanted to be sure that the two independent machines produced similar data.

This chart correct at 10/09/2002

I am currently building two backplanes. These will be fitted into crates prior to being installed into the rack.

Board TypeSerial NumberComponents AvailableAssembledTestedInstalled
SAMPLER001
SAMPLER002
SAMPLER003
SAMPLER004
SAMPLER005
SAMPLER006
SAMPLER007
SAMPLER008
SAMPLER009
SAMPLER010
Board TypeSerial NumberComponents AvailableAssembledTestedInstalled
LED DISPLAY001
LED DISPLAY002
LED DISPLAY003
LED DISPLAY004
LED DISPLAY005
LED DISPLAY006
LED DISPLAY007
LED DISPLAY008
LED DISPLAY009
LED DISPLAY010
Board TypeSerial NumberComponents AvailableAssembledTestedInstalled
INTERFACE001
INTERFACE002
INTERFACE003
INTERFACE004
INTERFACE005
INTERFACE006
INTERFACE007
INTERFACE008
INTERFACE009
INTERFACE010
Board TypeSerial NumberComponents AvailableAssembledTestedInstalled
LO MODULE001
LO MODULE002
LO MODULE003
LO MODULE004
LO MODULE005
LO MODULE006
LO MODULE007
LO MODULE008
LO MODULE009
LO MODULE010
Board TypeSerial NumberComponents AvailableAssembledTestedInstalled
BACKPLANE001
BACKPLANE002
BACKPLANE003
Board TypeSerial NumberComponents AvailableAssembledTestedInstalled
FILTER/PB001
FILTER/PB002
FILTER/PB003
FILTER/PB004
FILTER/PB005
FILTER/PB006
FILTER/PB007
FILTER/PB008
FILTER/PB009
FILTER/PB010
FILTER/PB011
FILTER/PB012
FILTER/PB013
FILTER/PB014
FILTER/PB015
FILTER/PB016
FILTER/PB017
FILTER/PB018
FILTER/PB019
FILTER/PB020
Board TypeSerial NumberComponents AvailableAssembledTestedInstalled
FILTER/LP001
FILTER/LP002
FILTER/LP003
FILTER/LP004
FILTER/LP005
FILTER/LP006
FILTER/LP007
FILTER/LP008
FILTER/LP009
FILTER/LP010
FILTER/LP011
FILTER/LP012
FILTER/LP013
FILTER/LP014
FILTER/LP015
FILTER/LP016
FILTER/LP017
FILTER/LP018
FILTER/LP019
FILTER/LP020
FILTER/LP021
FILTER/LP022
FILTER/LP023
FILTER/LP024
FILTER/LP025
FILTER/LP026
FILTER/LP027
FILTER/LP028
FILTER/LP029
FILTER/LP030
FILTER/LP031
FILTER/LP032
FILTER/LP033
FILTER/LP034
FILTER/LP035
FILTER/LP036
FILTER/LP037
FILTER/LP038
FILTER/LP039
FILTER/LP040

Written by Tim Ikin