Base line restoration (BLR)

Launch RHB
  • Launch RHB -r in the directory of the active experiment (“gotoexp“).
  • Click on OSC in the ROOT histogram viewer and look for the channel to setup.
  • Click at bottom to refresh only OSC and Counters (lighter).
  • Click on “Markers” in the top left corner of the OSC page.
Launch channel setup
  • Stop daq in fds.
  • In fds, type “channel_on_setup <channel number>” for the channel to set: this starts the DAQ for this channel only, generating a lighter data flow for RHB.
  • Move channel setup window to the workspace where RHB is running.
  • Right-click on channel setup window -> “always on top”.
BLR settings

Instructions below are for the “Dynamic BLR” mode in the channel setup.

  • Increase the sampling rate to 10 or 100 Hz.
  • The BLR threshold should be small, slightly above noise. To see the noise on the input signal, select “raw input” sampling, click on “without trig” in the trigger section. Zoom in y (V) around the baseline to see the noise and unzoom in x (t). Evaluate the peak-to-peak noise voltage. You can use this peak-to-peak noise amplitude as a starting value for the BLR threshold.
  • Now, select the “input trigger” sampling.
  • Unclick “without trig”.
  • Set the sampling delay to 25 % to display the baseline before the signal.
  • Zoom in y (V) on the baseline to a scale of tens of mV.
  • The baseline should be centered on 0 V.
  • If the baseline is not stable around 0, reduce the BLR gate length or adjust the Fc BLR cut-off frequency and/or the threshold, until the baseline remains centered on 0 V.
  • Reduce the sampling rate to 1 Hz.
  • Close the channel setup window.
  • Go back to fds. Answer “y” or “Y” to save the channel settings.
  • You can copy the BLR channel settings to another channel / group of channels of the same type by using the channel_copy command in fds, and using the option 2 (-> BLR).