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Correlation Spectrometer

The existing correlator is largely under manual control with a few limited functions under computer control via the DIO on the HP 1000.

The functions under computer control which must be reproduced in the NCCS are :

$\surd$
start correlator (output)
$\surd$
read data ready signal (input)
$\surd$
read 16-bit parallel data from the correlator (input),
$\surd$
``fix'' data as is done by ACFIN program on HP 1000 (to produce an auto- or cross-correlation function)
$\surd$
transmit correlator data (raw and/or fixed) to master computer and convert correlation function to spectrum.
These functions are presently implemented via a dedicated interface consisting of 2 control lines and 16 data lines.

The new correlator interface will be based on a PC. It will look like a black box to the master computer and will be interfaced via Ethernet or RS-422 or HPIB.

In addition to the above mandatory commands the new system should accept the following commands (cf. A Proposed Configuration for the New Control Computer System (NCSS)) :

$\heartsuit$
select video signal bandwidth,
$\heartsuit$
select correlator bandwidth,
$\heartsuit$
set video signal level via computer-controlled attenuators,
$\heartsuit$
reset correlator,
$\heartsuit$
set most significant bits of the correlator count (i.e. replace thumbwheel switches),
$\heartsuit$
setup correlator quadrant configuration,


next up previous contents
Next: Pulsar Timer Up: Hardware Previous: Slow Data Acquisition
Mike Gaylard
1999-06-11