10sep12 debugging 32 chan raw mode


links to sections:
Before the fix
After the fix
Links to plots:
plots show the out of order  data from file .0809.. 32channel,200MHz  (.ps) (.pdf):
the  results after the  fpga image was updated (ps) (.pdf)

The problem:

    Project p2676 took puppi data with 32 chan, 200 MHz bw, raw mode on 09aug12. The pulsar did not appear in the data. Looking at the radar rfi in the band, it looked like the radar freq was getting spread over  8 different channels (one in each gpu) rather than showing up in a single channel.

Resolution: Paul found that the reorder fpga was using an older version.. It was updated 10aug12 around noon.

The tests:

    On 10sep12 we did a test where a sine wave was injected into polA of  puppi (polB had its input terminated). The setup was:

Morning session (before fpga image switched).

Data was taken in the morning session:

    Looking at the the rms on the gpu's, the problem was still occurring. Power was showing up in 8 gpus rather than the single channel.

The plots show the out of order  data from file .0809.. 32channel,200MHz  (.ps) (.pdf):

Morning summary:

processing: x101/120910/puppisine_1.pro

Afternoon session (after fpga image switched).

    Paul noticed that the image for the reordering fpga was out of date. He updated the image to the same version that guppi (at greenbank) was using.
Dana and i repeated the tests in the afternoon (after the image was updated).

    The only setup change was that the power was increased by 6db (-24dbm out of the synth). Running guppi_adc_hist gave +/- 50 counts as the maximum for the histogram.

The data taken was:

Looking at the data:

    The files (0811) were copied (not moved)  from the 8 gpu's to:

This is the data after the fpga image was updated. Some idl routines were then used to look at the raw data samples.

The plots show the  results after the  fpga image was updated (ps) (.pdf)


processing: x101/120910/puppisine.pro

<- page up to puppi