# Measurement class for sweeping voltages and measuring voltage
import time
import numpy as np
[docs]def create_list(logger, cycle, max_val, min_val, step):
"""
Create a list of values based on the specified cycle type and parameters.
Args:
logger (logging.Logger): The logger object to use for logging messages.
cycle (str): The cycle type. Valid values are '+', '-', '+-', '-+'.
max_val (float): The maximum value for the list.
min_val (float): The minimum value for the list.
step (float): The step size between consecutive values.
Returns:
numpy.ndarray: The generated list of values, rounded to 5 decimal places.
Raises:
ValueError: If the cycle type is invalid.
"""
list_positive = np.concatenate((np.arange(0, max_val, step), [max_val], np.flip(np.arange(0, max_val, step))))
list_negative = np.concatenate((np.arange(0, min_val, -step), [min_val], np.flip(np.arange(0, min_val, -step))))
try:
match cycle:
case '+': return list_positive
case '-': return list_negative
case '+-': return np.concatenate((list_positive, list_negative))
case '-+': return np.concatenate((list_negative, list_positive))
except:
logger.critical('Invalid cycle type!')
quit()
[docs]class Measurement:
def __init__(self, logger, config, instrument):
"""
Initialize the Measurement class.
Args:
logger (logging.Logger): Logger to use for logging messages.
config (dict): Dictionary containing configuration parameters.
instrument (Instrument): Instrument object to use for measurement.
"""
self.name = 'sweepVI'
self.nparams = ['cycle', 'n_cycles', 'i+', 'i-', 'i_step', 'vcplc+','vcplc-', 't_sweep', 'nplc']
self.headers = ['Current [A]', 'Voltage [V]', 'Resistance [Ω]', 'Timer [s]', 'Datetime']
self.params = dict(config.items())
self.vals = create_list(
logger,
self.params.get(self.name).get('cycle'),
self.params.get(self.name).get('i+'),
self.params.get(self.name).get('i-'),
self.params.get(self.name).get('i_step')
)
self.set_plot_parameters(self.params.get(self.name).get('cycle'))
self.initialize_instrument(logger, instrument)
[docs] def set_plot_parameters(self, cycle_type):
"""
Set parameters for the plot based on the type of cycle.
Args:
cycle_type (str): Type of the cycle which could be '1' or '2'.
"""
match len(cycle_type):
case 1:
self.plot_grid = (2, 2)
self.plot_titles = [[f'Cycle V-I {cycle_type}', 'Resistance vs Time'],
['Resistance vs Voltage', 'Current vs Time']]
self.plot_labels = [
[['Current [A]','Voltage [V]'],
['Time [s]', 'Resistance [Ω]']],
[['Current [A]', 'Resistance [Ω]'],
['Time [s]', 'Current [A]']]]
self.plot_clear = [[True, False], [True, False]]
case 2:
self.plot_grid = (2, 3)
self.plot_titles = [['Cycle V-I +', 'Cycle V-I -', 'Resistance vs Time'],
['Resistance vs Current +', 'Resistance vs Current -', 'Current vs Time']]
self.plot_labels = [
[['Current [A]','Voltage [V]'], [ 'Current [A]', 'Voltage [V]'], ['Time [s]', 'Resistance [Ω]']],
[['Current [A]', 'Resistance [Ω]'], ['Current[A]', 'Resistance [Ω]'], ['Time [s]', 'Current [A]']]]
self.plot_clear = [[True, True, False], [True, True, False]]
[docs] def initialize_instrument(self, logger, instrument):
"""
Initialize the instrument with initial parameters.
Args:
logger (logging.Logger): Logger to use for logging messages.
instrument (Instrument): Instrument object to use for setting parameters.
"""
logger.debug('Setting instrument initial parameters')
instrument.reset(logger)
instrument.set_mode_fixed(logger, func="Current")
instrument.set_src_func(logger, func="Current")
instrument.set_sense_func(logger, func="Current")
instrument.set_func_range(logger, func="Current")
instrument.set_func_nplc(logger, func="Current", value=self.params.get(self.name).get('nplc'))
instrument.set_sense_func(logger, func="Voltage")
instrument.set_func_range(logger, func="Voltage")
logger.debug('Instrument parameters set!')
[docs] def measure_val(self, logger, instrument, val):
"""
Measure the output for a given current and return the result along with the plots.
Args:
logger (logging.Logger): Logger to use for logging messages.
instrument (Instrument): Instrument object to use for measurement.
val (float): The current value to measure.
Returns:
list: A list containing the result of measurement and the plots.
"""
if val>0: instrument.set_func_cplc(logger, func="Voltage", value=self.params.get(self.name).get('vcplc+'))
else: instrument.set_func_cplc(logger, func="Voltage", value=self.params.get(self.name).get('vcplc-'))
instrument.set_output_value(logger, "Current", val)
result_sweep = instrument.read(logger)
time.sleep(self.params.get(self.name).get('t_sweep'))
result = [
val, #Current [0]
result_sweep[0], #Voltage [1]
result_sweep[0]/val, #Resistance [2]
result_sweep[3], #Timer [3]
time.strftime("%Y-%m-%d %H:%M:%S", time.localtime()) #Datetime [4]
]
match len(self.params.get(self.name).get('cycle')):
case 1:
result_plots = [
[[result[0], result[1]], # [Current, Voltage] Cycle V-I
[result[3], result[2]]], # [Timer, Resistance] Resistance vs Time
[[result[0], result[2]], # [Current, Resistance] Resistance vs Voltage
[result[3], result[0]]] # [Timer, Current] Current vs Time
]
case 2:
if val >= 0:
result_plots = [
[[result[0], result[1]], # [Current, Voltage] Cycle V-I +
[np.nan, np.nan], # [NaN, NaN] Cycle V-I -
[result[3], result[2]]], # [Time, Resistance] Resistance vs Time
[[result[0], result[2]], # [Current, Resistance] Resistance vs Current +
[np.nan, np.nan], # [NaN, NaN] Resistance vs Current -
[result[3], result[0]]] # [Time, Current] Current vs Time
]
else:
result_plots = [
[[np.nan, np.nan], # [NaN, NaN] Cycle V-I +
[result[0], result[1]], # [Current, Voltage] Cycle V-I -
[result[3], result[2]]], # [Time, Resistance] Resistance vs Time
[[np.nan, np.nan], # [NaN, NaN] Resistance vs Current +
[result[0], result[2]], # [Current, Resistance] Resistance vs Current -
[result[3], result[0]]] # [Time, Current] Current vs Time
]
return [result, result_plots]