Differences
This shows you the differences between two versions of the page.
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pulsarinstruments:psrix_psrix2:psrix2:gain_atten_ctrl [2019/07/04 15:31] ramesh created |
pulsarinstruments:psrix_psrix2:psrix2:gain_atten_ctrl [2020/05/08 21:57] (current) ramesh |
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| The power input to the ROACH2s can be controlled by the Raspberry Pi integrated in to the gain box. A feedback on the power levels are only possible by consulting the output of the ROACH2 ADCs (either ADC histograms or the output of the PFB-FFT). This of course will only be possible if the ROACH2 FPGA is programmed appropriately, or configured with the right gateware. | The power input to the ROACH2s can be controlled by the Raspberry Pi integrated in to the gain box. A feedback on the power levels are only possible by consulting the output of the ROACH2 ADCs (either ADC histograms or the output of the PFB-FFT). This of course will only be possible if the ROACH2 FPGA is programmed appropriately, or configured with the right gateware. | ||
| - | - connect to the VNC session asterix:4 | + | - connect to the VNC session asterix:4 (use CrabPulsar to connect). |
| - | - load a firmware that has some ADC interfaces. eg. ''python /home/pulsar/roach2/r3xcontrol.py'' | + | - load a firmware that has some ADC interfaces. eg. ''python /home/pulsar/roach2/NewFirmware/r3xsetup_new.py'' |
| - | - start the ADC displays now: ''python /home/pulsar/roach2/r3xadchist.py'' | + | - start the ADC displays now: ''python /home/pulsar/roach2/NewFirmware/r3xadchist_new.py'' |
| - Now change the attenuator setting from another terminal: ''roach2attn <id> <atten>'', where id is 1,2,3 or 4, and attenuation is in the range of 0.5-30.5 dB in steps of 0.5. See example in the screen shot below. | - Now change the attenuator setting from another terminal: ''roach2attn <id> <atten>'', where id is 1,2,3 or 4, and attenuation is in the range of 0.5-30.5 dB in steps of 0.5. See example in the screen shot below. | ||
| - Consult the setting on the histogram above - aim to get the signal between -50 to +50. You should see something similar to the plot in the image below. | - Consult the setting on the histogram above - aim to get the signal between -50 to +50. You should see something similar to the plot in the image below. | ||
