Output Files

Output files from the PrM DAQ are saved in the data_files_path directory specified in the settings.yaml configuration file. The files are in npz and/or text format (configurable in settings.yaml). They contain the following information:

  • ch_A: numpy array containg waveform from channel A

  • ch_B: numpy array containg waveform from channel B

  • ch_time: time data was taken in Y-m-d H:M:S.f

  • run: run number

  • date: date data was taken in Ymd-HMS format

  • hv: ‘on’ or ‘off’

  • comment: the comment if any

  • hv_anode: value of anode HV [V]

  • hv_anodegrid: value of anode grid HV [V]

  • hv_cathode: value of cathode HV [V]

  • samples_per_sec: number of acquired samples per second

  • pre_trigger_samples: number of pretrigger samples

  • post_trigger_samples: number of posttrigger samples

  • input_range_volts: input range in Volts

Opening an Output file

The npz outputs can be opened like:

import numpy as np
container = np.load('file_name.npz')

cathode_wvf = container['ch_A']
anode_wvf = container['ch_B']
samples_per_sec = container['samples_per_sec']

x = np.arange(len(cathode_wvf)) / samples_per_sec * 1e3 # ms

fig, ax = plt.subplots(ncols=1, nrows=2, figsize=(12, 8), sharex=True)

fig.subplots_adjust(hspace=0)

x_scale = 1
y_scale = 1e3

ax[1].plot(x * x_scale, anode_on * y_scale,   label='Cathode')
ax[0].plot(x * x_scale, cathode_on * y_scale, label='Anode')
Example PrM Waveforms

The text outputs are of the form:

ch_A=[[0.11534820667744995,-1.0751930546414368,...]]
ch_B=[[-1.2907774641861673,0.19290700054296683,...]]
ch_time=2024-01-26 19:41:36.658627
run=301
date=20240126-194136
hv=off
...

If reading these with python the method literal_eval() of the built-in ast library is useful for converting the list strings to python lists