class Measurement(MeasurementBase):
params = {
'Vgs': Sweep([0.]),
'Vchucks': Sweep([0.]),
'Rg': 100e3,
'stabilise_time': 5.,
'stab_chuck_time': 5.,
'comment': String(''),
'data_dir': Folder(r'D:\MeasurementJANIS\Holger\test'),
'use_vna': Boolean(
True
), # when switched off, this script is basically just a leak test
'init_bilt': Boolean(
False
), # when switched on, the Bilt sources will be initialised, this might be dangerous for the sample
}
observables = ['Vg', 'Vchuck', 'Vgm', 'Ileak']
alarms = [['np.abs(Ileak) > 1e-8', MeasurementBase.ALARM_CALLCOPS]]
def measure(self, data_dir, Vgs, Vchucks, Rg, comment, stabilise_time,
stab_chuck_time, use_vna, init_bilt, **kwargs):
print("===================================")
print("Starting acquisition script...")
chuck_string = ''
vna_string = ''
# initialise instruments
print("Setting up DC sources and voltmeters...")
bilt = Bilt('TCPIP0::192.168.0.2::5025::SOCKET')
if init_bilt:
# source (bilt, channel, range, filter, slope in V/ms, label):
self.sourceVg = sourceVg = BiltVoltageSource(
bilt, "I1", "12", "1", 0.005, "Vg")
else:
self.sourceVg = sourceVg = BiltVoltageSource(bilt,
"I1",
initialise=False)
# voltmeter (bilt, channel, filt, label=None)
self.meterVg = meterVg = BiltVoltMeter(bilt, "I5;C1", "2", "Vgm")
print("DC sources and voltmeters are set up.")
print("Setting up Yokogawa for chuck voltage...")
# connect to the Yoko without initialising, this will lead to
# an exception if the Yoko is not properly configured (voltage
# source, range 30V, output ON)
self.yoko = yoko = Yoko7651('GPIB::3::INSTR',
initialise=False,
rang=30,
slope=1.)
print("Yokogawa is set up.")
if use_vna:
print("Setting up VNA...")
vna = AnritsuVNA('GPIB::6::INSTR')
sweeptime = vna.get_sweep_time()
if vna.get_sweep_type() != 'FSEGM':
raise Exception('Please use segmented frequency sweep')
# check if the RF power is the same on both ports and for all
# frequency segments
count = int(vna.query(':SENS:FSEGM:COUN?'))
vna_pow = None
for i in range(1, count + 1):
port1pow = float(
vna.query(':SENS:FSEGM{}:POW:PORT1?'.format(i)))
port2pow = float(
vna.query(':SENS:FSEGM{}:POW:PORT2?'.format(i)))
if vna_pow is None and port1pow == port2pow:
vna_pow = port1pow
elif vna_pow is not None and port1pow == port2pow and port1pow == vna_pow:
continue
else:
raise Exception(
"Please select the same power for all ports and frequency segments"
)
port1att = vna.get_source_att(1)
port2att = vna.get_source_att(2)
if port1att == port2att:
vna_pow -= port1att
else:
raise Exception(
"Please select the same attenuators for both ports")
vna_string = '_pwr={:.0f}'.format(vna_pow)
print("VNA is set up.")
# prepare saving DC data
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
filename = timestamp + vna_string + ('_' + comment if comment else '')
self.prepare_saving(os.path.join(data_dir, filename + '.txt'))
if use_vna:
# prepare saving RF data
spectra_fol = os.path.join(data_dir, filename)
create_path(spectra_fol)
# save segmented frequency sweep data to file
with open(os.path.join(spectra_fol, 'VNAconfig'), 'w') as f:
vna.dump_freq_segments(f)
for Vchuck in Vchucks:
print("Setting Vchuck = {}".format(Vchuck))
# set Vchuck
yoko.set_voltage(Vchuck)
# wait
time.sleep(stab_chuck_time)
for Vg in Vgs:
if self.flags['quit_requested']:
print("Stopping acquisition.")
return locals()
print("Setting Vg = {}".format(Vg))
# set Vg
sourceVg.set_voltage(Vg)
# wait
time.sleep(stabilise_time)
# read voltages
Vgm = meterVg.get_voltage()
# do calculations
Ileak = (Vg - Vgm) / Rg
# save DC data
self.save_row(locals())
if use_vna:
# save VNA data
print("Getting VNA spectra...")
vna.single_sweep(wait=False)
# display sweep progress
progressbar_wait(sweeptime)
# make sure sweep is really done
while not vna.is_sweep_done():
time.sleep(0.5)
table = vna.get_table([1, 2, 3, 4])
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
spectrum_file = timestamp + '_Vg={:.3f}_Vchuck={:.1f}.txt'.format(
Vg, Vchuck)
np.savetxt(os.path.join(spectra_fol, spectrum_file),
np.transpose(table))
print("Acquisition done.")
return locals()
def tidy_up(self):
self.end_saving()
print("Driving all voltages back to zero...")
self.sourceVg.set_voltage(0.)
self.yoko.set_voltage(0.)
class Measurement(MeasurementBase):
params = {
'Vgs': Sweep([0.]),
'stabilise_time': 0.3,
'init': Boolean(True),
'use_vna': Boolean(True),
'comment': String(''),
'data_dir': Folder(r'D:\MeasurementJANIS\Holger\test')
}
observables = ['Vg', 'Ileak']
alarms = [
['np.abs(Ileak) > 1e-8', MeasurementBase.ALARM_CALLCOPS] # is applied between the two gates
]
def measure(self, Vgs, stabilise_time, init, use_vna, data_dir, comment, **kwargs):
print("===================================")
print("Starting acquisition script...")
vna_string = ''
# initialise instruments
try:
print("----------------------------------------")
print("Setting up Keithley DC sources...")
self.sourceVg = sourceVg = K2400('GPIB::24::INSTR', sourcemode='v', vrang=200, irang=10e-6, slope=1, initialise=init)
print("DC sources are set up.")
except:
print("There has been an error setting up DC sources.")
raise
if use_vna:
print("Setting up VNA...")
vna = AnritsuVNA('GPIB::6::INSTR')
sweeptime = vna.get_sweep_time()
if vna.get_sweep_type() != 'FSEGM':
raise Exception('Please use segmented frequency sweep')
# check if the RF power is the same on both ports and for all
# frequency segments
count = int(vna.query(':SENS:FSEGM:COUN?'))
vna_pow = None
for i in range(1,count+1):
port1pow = float(vna.query(':SENS:FSEGM{}:POW:PORT1?'.format(i)))
port2pow = float(vna.query(':SENS:FSEGM{}:POW:PORT2?'.format(i)))
if vna_pow is None and port1pow == port2pow:
vna_pow = port1pow
elif vna_pow is not None and port1pow == port2pow and port1pow == vna_pow:
continue
else:
raise Exception("Please select the same power for all ports and frequency segments")
port1att = vna.get_source_att(1)
port2att = vna.get_source_att(2)
if port1att == port2att:
vna_pow -= port1att
else:
raise Exception("Please select the same attenuators for both ports")
vna_string = '_pwr={:.0f}'.format(vna_pow)
print("VNA is set up.")
# define name
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
filename = timestamp + vna_string + ('_'+comment if comment else '')
# prepare saving RF data
spectra_fol = os.path.join(data_dir, filename)
create_path(spectra_fol)
# prepare saving DC data
self.prepare_saving(os.path.join(data_dir, filename + '.txt'))
if use_vna:
# prepare saving RF data
spectra_fol = os.path.join(data_dir, filename)
create_path(spectra_fol)
# save segmented frequency sweep data to file
with open(os.path.join(spectra_fol, 'VNAconfig'), 'w') as f:
vna.dump_freq_segments(f)
# loop
for Vg in Vgs:
if self.flags['quit_requested']:
return locals()
print('Setting Vg='+str(Vg)+' V...')
sourceVg.set_voltage(Vg)
time.sleep(stabilise_time)
# measure
Vgm = sourceVg.get_voltage()
Ileak = sourceVg.get_current()
# save data
self.save_row(locals())
# save VNA data
if use_vna:
# save VNA data
print("Getting VNA spectra...")
vna.single_sweep(wait=False)
# display sweep progress
progressbar_wait(sweeptime)
# make sure sweep is really done
while not vna.is_sweep_done():
time.sleep(0.5)
table = vna.get_table([1,2,3,4])
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
spectrum_file = timestamp+'_Vg={:.3f}.txt'.format(Vg)
np.savetxt(os.path.join(spectra_fol, spectrum_file), np.transpose(table))
print("Acquisition done.")
return locals()
def tidy_up(self):
self.end_saving()
print("Driving all voltages back to zero...")
self.sourceVg.set_voltage(0.)
class Measurement(MeasurementBase):
params = {
'Vgs': Sweep([0.]),
'Rg': 100e3,
'stabilise_time': 0.3,
'comment': String(''),
'data_dir': Folder(r'D:\MeasurementJANIS\Holger\test'),
'use_vna': Boolean(True),
'use_chuck': Boolean(
True
), # we are not controlling the chuck here, just recording the value of the chuck voltage
'init_bilt': Boolean(False)
}
observables = ['Vg', 'Vgm', 'Ileak']
alarms = [['np.abs(Ileak) > 1e-8', MeasurementBase.ALARM_CALLCOPS]]
def measure(self, data_dir, Vgs, Rg, comment, stabilise_time, use_vna,
use_chuck, init_bilt, **kwargs):
print("===================================")
print("Starting acquisition script...")
chuck_string = ''
vna_string = ''
# initialise instruments
print("Setting up DC sources and voltmeters...")
bilt = Bilt('TCPIP0::192.168.0.2::5025::SOCKET')
if init_bilt:
# source (bilt, channel, range, filter, slope in V/ms, label):
self.sourceVg = sourceVg = BiltVoltageSource(
bilt, "I1", "12", "1", 0.005, "Vg")
else:
self.sourceVg = sourceVg = BiltVoltageSource(bilt,
"I1",
initialise=False)
# voltmeter (bilt, channel, filt, label=None)
self.meterVg = meterVg = BiltVoltMeter(bilt, "I5;C1", "2", "Vgm")
print("DC sources and voltmeters are set up.")
if use_chuck:
print("Setting up Yokogawa for chuck voltage...")
# connect to the Yoko without initialising, this will lead to
# an exception if the Yoko is not properly configured (voltage
# source, range 30V, output ON)
yoko = Yoko7651('GPIB::3::INSTR', initialise=False, rang=30)
chuck_string = '_Vchuck={:.1f}'.format(yoko.get_voltage())
print("Yokogawa is set up.")
if use_vna:
print("Setting up VNA")
self.vna = vna = RohdeSchwarzVNA()
vna.open('GPIB', '20')
c1 = vna.channel(1)
sweeptime = c1.total_sweep_time_ms
c1.manual_sweep = True
c1.s_parameter_group = c1.to_logical_ports((1, 2))
# cf: https://www.rohde-schwarz.com/webhelp/webhelp_zva/program_examples/basic_tasks/typical_stages_of_a_remote_control_program.htm#Command_Synchronization
vna.write("*SRE 32")
vna.write("*ESE 1")
if not c1.sweep_type == 'SEGM': # need to use not == because != is not implemented in Rohde Schwarz library
raise Exception('Please use segmented frequency sweep')
# check if the RF power is the same on both ports and for all
# frequency segments
count = int(vna.query(':SENS:SEGM:COUN?').strip())
vna_pow = None
for i in range(1, count + 1):
seg_pow = float(vna.query(':SENS:SEGM{}:POW?'.format(i)))
if vna_pow is None:
vna_pow = seg_pow
elif vna_pow is not None and seg_pow == vna_pow:
continue
else:
raise Exception(
"Please select the same power for all ports and frequency segments"
)
port1autoatt = int(vna.query(':SOUR:POW1:ATT:AUTO?').strip())
port2autoatt = int(vna.query(':SOUR:POW2:ATT:AUTO?').strip())
if port1autoatt or port2autoatt:
raise Exception("Please do not use automatic attenuators")
port1att = float(vna.query(':SOUR:POW1:ATT?').strip())
port2att = float(vna.query(':SOUR:POW2:ATT?').strip())
if port1att == port2att:
vna_pow -= port1att
else:
raise Exception(
"Please select the same attenuators for both ports")
vna_string = '_pwr={:.0f}'.format(vna_pow)
print("VNA is set up.")
# prepare saving DC data
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
filename = timestamp + vna_string + chuck_string + ('_' + comment
if comment else '')
self.prepare_saving(os.path.join(data_dir, filename + '.txt'))
if use_vna:
# prepare saving RF data
spectra_fol = os.path.join(data_dir, filename)
create_path(spectra_fol)
with open(os.path.join(spectra_fol, 'VNAconfig'), 'w') as f:
f.write(
'# Frequency based segmented sweep setup of Rohde&Schwarz ZVA 67\n'
)
f.write('# Attenuator Port 1: {}\n'.format(port1att))
f.write('# Attenuator Port 2: {}\n'.format(port2att))
f.write('# Seg no.\tfstart\tfstop\tpoints\tbwidth\tpow\n')
count = int(vna.query(':SENS:SEGM:COUN?').strip())
for i in range(1, count + 1):
seg_pow = float(
vna.query(':SENS:SEGM{}:POW?'.format(i)).strip())
bwidth = float(
vna.query(':SENS:SEGM{}:BWID?'.format(i)).strip())
fstart = float(
vna.query(':SENS:SEGM{}:FREQ:STAR?'.format(i)).strip())
fstop = float(
vna.query(':SENS:SEGM{}:FREQ:STOP?'.format(i)).strip())
points = int(
vna.query(':SENS:SEGM{}:SWE:POIN?'.format(i)).strip())
f.write('{:d}\t{:f}\t{:f}\t{:d}\t{:f}\t{:f}\n'.format(
i, fstart, fstop, points, bwidth, seg_pow))
for Vg in Vgs:
if self.flags['quit_requested']:
print("Stopping acquisition.")
return locals()
print("Setting Vg = {}".format(Vg))
# set Vg
sourceVg.set_voltage(Vg)
# wait
time.sleep(stabilise_time)
# read voltages
Vgm = meterVg.get_voltage()
# do calculations
Ileak = (Vg - Vgm) / Rg
# save DC data
self.save_row(locals())
if use_vna:
# save VNA data
print("Getting VNA spectra...")
vna.write("INIT1:IMM; *OPC")
# display sweep progress
progressbar_wait(sweeptime / 1e3)
# make sure sweep is really done
while not int(vna.query("*ESR?").strip()):
time.sleep(0.5)
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
spectrum_file = timestamp + '_Vg=%2.4f' % (Vg)
#vna.channel(1).save_measurement_locally(os.path.join(spectra_fol, spectrum_file), (1,2))
spectrum_file = os.path.join(spectra_fol,
spectrum_file + '.s2p')
unique_filename = unique_alphanumeric_string() + '.s2p'
scpi = ":MMEM:STOR:TRAC:PORT {0},'{1}',{2},{3}"
scpi = scpi.format(1, \
unique_filename, \
'COMP', \
'1,2')
vna.write(scpi)
# this saves the file on the ZVA in the folder
# C:\Rohde&Schwarz\Nwa\
vna.pause(5000)
vna.file.download_file(unique_filename, spectrum_file)
vna.file.delete(unique_filename)
print("Acquisition done.")
return locals()
def tidy_up(self):
self.vna.close()
self.end_saving()
print("Driving all voltages back to zero...")
self.sourceVg.set_voltage(0.)
class Measurement(MeasurementBase):
params = {
'Vg1s': Sweep([0.0]),
'Vg2s': Sweep([0.0]),
'commongate': Boolean(False),
'Rg1': 100e3,
'Rg2': 100e3,
'Rds': 2.2e3,
'stabilise_time': 0.5,
'comment': String(''),
'data_dir': Folder(r'D:\meso\Desktop\testdata')
}
observables = [
'Vg1', 'Vg1m', 'Ileak1', 'Vg2', 'Vg2m', 'Ileak2', 'Vds', 'Vdsm',
'Vdsm_std', 'Rs'
]
alarms = [
['np.abs(Ileak1) > 1e-8', MeasurementBase.ALARM_CALLCOPS],
['np.abs(Ileak2) > 1e-8', MeasurementBase.ALARM_CALLCOPS],
['np.abs(Vg1-Vg2)', MeasurementBase.ALARM_SHOWVALUE
] # useful if we just want to know how much voltage
# is applied between the two gates
]
def measure(self, data_dir, Vg1s, Vg2s, commongate, Rg1, Rg2, Rds,
stabilise_time, **kwargs):
print("===================================")
print("Starting acquisition script...")
# initialise instruments
try:
print("Setting up DC sources and voltmeters...")
bilt = Bilt('TCPIP0::192.168.0.2::5025::SOCKET')
self.sourceVg1 = sourceVg1 = BiltVoltageSource(
bilt, "I2", "12", "1", 0.01, "Vg1")
self.sourceVg2 = sourceVg2 = BiltVoltageSource(
bilt, "I3", "12", "1", 0.01, "Vg2")
self.meterVg1 = meterVg1 = BiltVoltMeter(bilt, "I5;C2", "2",
"Vg1m")
self.meterVg2 = meterVg2 = BiltVoltMeter(bilt, "I5;C3", "2",
"Vg2m")
print("DC sources and voltmeters are set up.")
except:
print(
"There has been an error setting up DC sources and voltmeters."
)
raise
try:
print("Setting up lock-in amplifier")
self.lockin = lockin = ZILockin()
print("Lock in amplifier is set up.")
except:
print("There has been an error setting up the lock-in amplifier.")
raise
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
# save lock in settings (in case we need to check something later)
lockin.save_settings(
os.path.join(data_dir, 'ZIsettings',
timestamp + '.ZIsettings.txt'))
# prepare saving data
filename = timestamp + '.txt'
self.prepare_saving(os.path.join(data_dir, filename))
# loops
Vds = lockin.rms_amp
for Vg2 in Vg2s:
sourceVg2.set_voltage(Vg2)
for Vg1 in Vg1s:
if self.flags['quit_requested']:
return locals()
sourceVg1.set_voltage(Vg1)
# stabilise
time.sleep(stabilise_time)
# measure
Vg1m = meterVg1.get_voltage()
Vg2m = meterVg2.get_voltage()
Vdsm, Vdsm_std = lockin.poll_data()
# do calculations
Ileak1 = (Vg1 - Vg1m) / Rg1
Ileak2 = (Vg2 - Vg2m) / Rg2
Rs = Rds * Vdsm / (Vds - Vdsm)
# save data
self.save_row(locals())
print("Acquisition done.")
return locals()
def tidy_up(self):
self.end_saving()
print("Driving all voltages back to zero...")
self.sourceVg1.set_voltage(0.)
self.sourceVg2.set_voltage(0.)
self.lockin.tidy_up()
class Measurement(MeasurementBase):
params = {
'Vgs': Sweep([0.]),
'Rg': 100e3,
'stabilise_time': 0.3,
'comment': String(''),
'data_dir': Folder(r'D:\MeasurementJANIS\Holger\test'),
'use_vna': Boolean(True),
'use_chuck': Boolean(
True
), # we are not controlling the chuck here, just recording the value of the chuck voltage
'init_bilt': Boolean(False)
}
observables = ['Vg', 'Vgm', 'Ileak']
alarms = [['np.abs(Ileak) > 1e-8', MeasurementBase.ALARM_CALLCOPS]]
def measure(self, data_dir, Vgs, Rg, comment, stabilise_time, use_vna,
use_chuck, init_bilt, **kwargs):
print("===================================")
print("Starting acquisition script...")
chuck_string = ''
vna_string = ''
# initialise instruments
print("Setting up DC sources and voltmeters...")
bilt = Bilt('TCPIP0::192.168.0.5::5025::SOCKET')
if init_bilt:
# source (bilt, channel, range, filter, slope in V/ms, label):
self.sourceVg = sourceVg = BiltVoltageSource(
bilt, "I3;C1", "12", "1", 0.005, "Vg")
else:
self.sourceVg = sourceVg = BiltVoltageSource(bilt,
"I3;C1",
initialise=False)
# voltmeter (bilt, channel, filt, label=None)
self.meterVg = meterVg = BiltVoltMeter(bilt, "I1;C1", "2", "Vgm")
print("DC sources and voltmeters are set up.")
if use_chuck:
print("Setting up Yokogawa for chuck voltage...")
# connect to the Yoko without initialising, this will lead to
# an exception if the Yoko is not properly configured (voltage
# source, range 30V, output ON)
yoko = Yoko7651('GPIB::10::INSTR', initialise=False, rang=30)
chuck_string = '_Vchuck={:.1f}'.format(yoko.get_voltage())
print("Yokogawa is set up.")
if use_vna:
print("Setting up VNA")
self.vna = vna = RohdeSchwarzVNA()
vna.open('TCPIP', '192.168.0.3')
c1 = vna.channel(1)
sweeptime = c1.total_sweep_time_ms
c1.init_nonblocking_sweep((1, 2))
if not c1.is_corrected():
raise Exception('Please calibrate or switch on correction.')
if c1.sweep_type != 'SEGM':
raise Exception('Please use segmented frequency sweep')
# check if the RF power is the same on both ports and for all
# frequency segments
vna_pow = np.unique(np.asarray(c1.get_frequency_segments())[:, 5])
if len(vna_pow) > 1:
raise Exception(
"Please select the same power for all ports and frequency segments"
)
vna_pow = vna_pow[0]
if c1.is_auto_attenuator(1) or c1.is_auto_attenuator(2):
raise Exception("Please do not use automatic attenuators")
port1att = c1.get_attenuator(1)
if port1att == c1.get_attenuator(2):
vna_pow -= port1att
else:
raise Exception(
"Please select the same attenuators for both ports")
vna_string = '_pwr={:.0f}'.format(vna_pow)
print("VNA is set up.")
# prepare saving DC data
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
filename = timestamp + vna_string + chuck_string + ('_' + comment
if comment else '')
self.prepare_saving(os.path.join(data_dir, filename + '.txt'))
if use_vna:
# prepare saving RF data
spectra_fol = os.path.join(data_dir, filename)
create_path(spectra_fol)
c1.save_frequency_segments(os.path.join(spectra_fol, 'VNAconfig'))
for Vg in Vgs:
if self.flags['quit_requested']:
print("Stopping acquisition.")
return locals()
print("Setting Vg = {}".format(Vg))
# set Vg
sourceVg.set_voltage(Vg)
# wait
time.sleep(stabilise_time)
# read voltages
Vgm = meterVg.get_voltage()
# do calculations
Ileak = (Vg - Vgm) / Rg
# save DC data
self.save_row(locals())
if use_vna:
# save VNA data
print("Getting VNA spectra...")
c1.start_nonblocking_sweep()
# display sweep progress
progressbar_wait(sweeptime / 1e3)
# make sure sweep is really done
while not c1.isdone_nonblocking_sweep():
time.sleep(0.5)
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
spectrum_file = timestamp + '_Vg=%2.4f' % (Vg)
spectrum_file = os.path.join(spectra_fol,
spectrum_file + '.s2p')
c1.save_nonblocking_sweep(spectrum_file, (1, 2))
print("Acquisition done.")
return locals()
def tidy_up(self):
self.vna.close()
self.end_saving()
print("Driving all voltages back to zero...")
self.sourceVg.set_voltage(0.)
class Measurement(MeasurementBase):
params = {
'Vds': 10e-3,
'Vgs': Sweep([0.]),
'Rg': 100e3,
'stabilise_time': 0.05,
'init': Boolean(True),
'comment': String(''),
'data_dir': Folder('D:\Manip13\Desktop\Holger')
}
observables = ['Vg', 'Vgm', 'Ileak', 'Vds', 'Vdsm', 'Ids', 'Rds']
alarms = [['np.abs(Ileak) > 1e-8', MeasurementBase.ALARM_CALLCOPS
] # is applied between the two gates
]
def measure(self, Vds, Vgs, Rg, stabilise_time, init, data_dir, comment,
**kwargs):
print("===================================")
print("Starting acquisition script...")
# initialise instruments
try:
print("Setting up DC sources...")
self.sourceVg = sourceVg = K2400('GPIB::24::INSTR',
sourcemode='v',
vrang=200,
irang=10e-6,
slope=1,
initialise=init)
self.sourceVds = sourceVds = K2600('GPIB::26::INSTR',
slope=0.005,
initialise=init)
print("DC sources and voltmeters are set up.")
except:
print(
"There has been an error setting up DC sources and voltmeters."
)
raise
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
# prepare saving data
filename = timestamp + '_' + (comment if comment else '') + '.txt'
self.prepare_saving(os.path.join(data_dir, filename))
# loop
sourceVds.set_voltage(Vds)
for Vg in Vgs:
if self.flags['quit_requested']:
return locals()
print('Setting Vg=' + str(Vg) + ' V...')
sourceVg.set_voltage(Vg)
time.sleep(stabilise_time)
# measure
Vgm = sourceVg.get_voltage()
Ileak = sourceVg.get_current()
Vdsm = sourceVds.get_voltage()
Ids = sourceVds.get_current()
# do calculations
Rds = Vds / Ids
# save data
self.save_row(locals())
print("Acquisition done.")
return locals()
def tidy_up(self):
self.end_saving()
print("Driving all voltages back to zero...")
self.sourceVds.set_voltage(0.)
self.sourceVg.set_voltage(0.)
class Measurement(MeasurementBase):
params = {
'Vgs': Sweep([0.]),
'stabilise_time': 0.3,
'init': Boolean(True),
'use_vna': Boolean(True),
'comment': String(''),
'data_dir': Folder(r'D:\MeasurementJANIS\David M')
}
observables = ['Vg', 'Ileak']
alarms = [['np.abs(Ileak) > 1e-8', MeasurementBase.ALARM_CALLCOPS
] # is applied between the two gates
]
def measure(self, Vgs, stabilise_time, init, use_vna, data_dir, comment,
**kwargs):
print("===================================")
print("Starting acquisition script...")
vna_string = ''
# initialise instruments
try:
print("----------------------------------------")
print("Setting up Keithley DC sources...")
self.sourceVg = sourceVg = K2400('GPIB::24::INSTR',
sourcemode='v',
vrang=200,
irang=10e-6,
slope=1,
initialise=init)
print("DC sources are set up.")
except:
print("There has been an error setting up DC sources.")
raise
if use_vna:
try:
print("----------------------------------------")
print("Setting up VNA")
self.vna = vna = RohdeSchwarzVNA()
vna.open('TCPIP', '192.168.0.3')
c1 = vna.channel(1)
#check if we used a segmented sweep
c1.manual_sweep = True
c1.s_parameter_group = c1.to_logical_ports((1, 2))
vna.write("*SRE 32")
vna.write("*ESE 1")
if not c1.sweep_type == 'SEGM':
raise Exception('Please use segmented frequency sweep')
# check if the RF power is the same on both ports and for all frequency segments
count = int(vna.query(':SENS:SEGM:COUN?').strip())
vna_pow = None
for i in range(1, count + 1):
seg_pow = float(vna.query(':SENS:SEGM{}:POW?'.format(i)))
if vna_pow is None:
vna_pow = seg_pow
elif vna_pow is not None and seg_pow == vna_pow:
continue
else:
raise Exception(
"Please select the same power for all ports and frequency segments"
)
port1autoatt = int(vna.query(':SOUR:POW1:ATT:AUTO?').strip())
port2autoatt = int(vna.query(':SOUR:POW2:ATT:AUTO?').strip())
if port1autoatt or port2autoatt:
raise Exception("Please do not use automatic attenuators")
port1att = float(vna.query(':SOUR:POW1:ATT?').strip())
port2att = float(vna.query(':SOUR:POW2:ATT?').strip())
if port1att == port2att:
vna_pow -= port1att
else:
raise Exception(
"Please select the same attenuators for both ports")
vna_string = '_pwr={:.0f}'.format(vna_pow)
print("VNA is set up.")
except:
print("There has been an error setting up the VNA.")
raise
# define name
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
filename = timestamp + vna_string + ('_' + comment if comment else '')
# prepare saving RF data
spectra_fol = os.path.join(data_dir, filename)
create_path(spectra_fol)
# prepare saving DC data
self.prepare_saving(os.path.join(data_dir, filename + '.txt'))
# save config
if use_vna:
try:
with open(os.path.join(spectra_fol, 'VNAconfig'), 'w') as f:
f.write(
'# Frequency based segmented sweep setup of Rohde&Schwarz ZVA 67\n'
)
f.write('# Attenuator Port 1: {}\n'.format(port1att))
f.write('# Attenuator Port 2: {}\n'.format(port2att))
f.write('# Seg no.\tfstart\tfstop\tpoints\tbwidth\tpow\n')
count = int(vna.query(':SENS:SEGM:COUN?').strip())
for i in range(1, count + 1):
seg_pow = float(
vna.query(':SENS:SEGM{}:POW?'.format(i)).strip())
bwidth = float(
vna.query(':SENS:SEGM{}:BWID?'.format(i)).strip())
fstart = float(
vna.query(
':SENS:SEGM{}:FREQ:STAR?'.format(i)).strip())
fstop = float(
vna.query(
':SENS:SEGM{}:FREQ:STOP?'.format(i)).strip())
points = int(
vna.query(
':SENS:SEGM{}:SWE:POIN?'.format(i)).strip())
f.write('{:d}\t{:f}\t{:f}\t{:d}\t{:f}\t{:f}\n'.format(
i, fstart, fstop, points, bwidth, seg_pow))
except:
print("There has been an error setting up the VNA.")
raise
# loop
for Vg in Vgs:
if self.flags['quit_requested']:
return locals()
print('Setting Vg=' + str(Vg) + ' V...')
sourceVg.set_voltage(Vg)
time.sleep(stabilise_time)
# measure
Vgm = sourceVg.get_voltage()
Ileak = sourceVg.get_current()
# save data
self.save_row(locals())
# save VNA data
if use_vna:
print("Getting VNA spectra...")
#save data
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
spectrum_file = timestamp + '_Vg=%2.4f' % (Vg)
c1.save_measurement_locally(
os.path.join(spectra_fol, spectrum_file), (1, 2))
print("Acquisition done.")
return locals()
def tidy_up(self):
self.end_saving()
print("Driving all voltages back to zero...")
self.sourceVg.set_voltage(0.)
class Measurement(MeasurementBase):
params = {
'data_dir': Folder('/home/holger'),
'Vg1s': Sweep(np.linspace(-1., 1., 101)),
'Vg2s': Sweep([0.]),
'Vds': 10e-3,
'commongate': Boolean(False),
'Rg1': 100e3,
'Rg2': 100e3,
'Rds': 2.2e3,
'stabilise_time': 5,
'comment': String('comment')
}
observables = [
'Vg1', 'Vg1m', 'Ileak1', 'Vg2', 'Vg2m', 'Ileak2', 'Vds', 'Vdsm', 'Rs'
]
alarms = [
['np.abs(Ileak1) > 1e-8', MeasurementBase.ALARM_CALLCOPS],
['np.abs(Ileak2) > 1e-8', MeasurementBase.ALARM_CALLCOPS],
['np.abs(Vg1-Vg2)', MeasurementBase.ALARM_SHOWVALUE
] # useful if we just want to know how much voltage
# is applied between the two gates
]
def __init__(self, redirect_console=False, parent=None):
super(Measurement, self).__init__(redirect_console=redirect_console,
parent=parent)
time.sleep(0.5) # take some time to load
def measure(self, data_dir, Vg1s, Vg2s, Vds, commongate, Rg1, Rg2, Rds,
stabilise_time, **kwargs):
print("Starting acquisition script...")
print(
"Because I need to save my data somewhere, I will save it in the following directory:"
)
print(data_dir)
# initialise instruments
try:
self.sourceVg1 = sourceVg1 = VoltageSource(
) # here we should add safety limits
self.sourceVg2 = sourceVg2 = VoltageSource()
self.sourceVds = sourceVds = VoltageSource()
self.meterVg1 = meterVg1 = VoltMeter()
self.meterVg2 = meterVg2 = VoltMeter()
self.meterVds = meterVds = VoltMeter()
except:
print("There has been an error setting up one of the instruments.")
raise
# prepare saving data
filename = time.strftime('%Y-%m-%d_%Hh%Mm%Ss') + '.txt'
self.prepare_saving('testdata/' + filename)
# loops
sourceVds.set_voltage(Vds)
for Vg2 in Vg2s:
sourceVg2.set_voltage(Vg2)
for Vg1 in Vg1s:
if self.flags['quit_requested']:
return locals()
sourceVg1.set_voltage(Vg1)
# stabilise
progressbar_wait(stabilise_time)
# measure
Vg1m = meterVg1.get_voltage()
Vg2m = meterVg2.get_voltage()
Vdsm = meterVds.get_voltage()
# do calculations
Ileak1 = (Vg1 - Vg1m) / Rg1
Ileak2 = (Vg2 - Vg2m) / Rg2
Rs = Rds * Vdsm / (Vds - Vdsm)
# save data
self.save_row(locals())
print("Acquisition done.")
return locals()
def tidy_up(self):
self.end_saving()
print("Driving all voltages back to zero...")
self.sourceVg1.set_voltage(0.)
self.sourceVg2.set_voltage(0.)
self.sourceVds.set_voltage(0.)
class Measurement(MeasurementBase):
params = {
'Vdss': Sweep([10e-3]),
'Vg1s': Sweep([0.1]),
'Vg2s': Sweep([0.]),
'commongate': Boolean(False),
'Rg2': 100e3,
'Rds': 2.2e3,
'stabilise_time': 0.05,
'comment': String(''),
'data_dir': Folder(r'D:\MeasurementJANIS\Holger\test'),
'useVNA': Boolean(False),
}
observables = [
'Vg1', 'Vg2', 'Vg2m', 'Ileak2', 'Vds', 'Vdsm', 'Rs', 'Ta', 'Tb'
]
alarms = [
['np.abs(Ileak2) > 1e-8', MeasurementBase.ALARM_CALLCOPS],
['np.abs(Vg1-Vg2)', MeasurementBase.ALARM_SHOWVALUE
] # useful if we just want to know how much voltage
# is applied between the two gates
]
def measure(self, data_dir, comment, Vdss, Vg1s, Vg2s, commongate, Rg2,
Rds, stabilise_time, useVNA, **kwargs):
print("===================================")
print("Starting acquisition script...")
# initialise instruments
try:
print("Setting up DC sources and voltmeters...")
bilt = Bilt('TCPIP0::192.168.0.2::5025::SOCKET')
self.sourceVds = sourceVds = BiltVoltageSource(bilt,
"I1",
initialise=False)
self.sourceVg1 = sourceVg1 = BiltVoltageSource(bilt,
"I2",
initialise=False)
self.sourceVg2 = sourceVg2 = BiltVoltageSource(bilt,
"I3",
initialise=False)
self.meterVds = meterVds = BiltVoltMeter(bilt, "I5;C1", "2",
"Vdsm")
self.meterVg2 = meterVg2 = BiltVoltMeter(bilt, "I5;C3", "2",
"Vg2m")
print("DC sources and voltmeters are set up.")
except:
print(
"There has been an error setting up DC sources and voltmeters."
)
raise
if useVNA:
try:
print("Setting up VNA")
vna = AnritsuVNA('GPIB::6::INSTR')
self.freqs = vna.get_freq_list() # get frequency list
print("VNA is set up.")
except:
print("There has been an error setting up the VNA.")
raise
try:
print("Setting up temperature controller...")
tc = SI9700('GPIB::14::INSTR')
print("Temperature controller is set up.")
except:
print(
"There has been an error setting up the temperature controller."
)
raise
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
# prepare saving DC data
filename = timestamp + ('_' + comment if comment else '')
self.prepare_saving(os.path.join(data_dir, filename + '.txt'))
# prepare saving RF data
if useVNA:
spectra_fol = os.path.join(data_dir, filename)
try:
os.makedirs(spectra_fol)
except OSError as e:
if e.errno != errno.EEXIST:
raise
# loops
for Vds in Vdss:
sourceVds.set_voltage(Vds)
for Vg2 in Vg2s:
if not commongate:
sourceVg2.set_voltage(Vg2)
for Vg1 in Vg1s:
if self.flags['quit_requested']:
return locals()
sourceVg1.set_voltage(Vg1)
if commongate:
Vg2 = Vg1
sourceVg2.set_voltage(Vg1)
# stabilise
time.sleep(stabilise_time)
# measure
Vdsm = meterVds.get_voltage()
Vg2m = meterVg2.get_voltage()
Ta = tc.get_temp('a')
Tb = tc.get_temp('b')
# do calculations
Ileak2 = (Vg2 - Vg2m) / Rg2
Rs = Rds * Vdsm / (Vds - Vdsm)
# save data
self.save_row(locals())
# save VNA data
if useVNA:
print("Getting VNA spectra...")
vna.single_sweep()
table = vna.get_table(range(1, 5))
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
spectrum_file = timestamp + '_Vg1=%2.4f' % (
Vg1) + '_Vg2=%2.4f' % (Vg2) + '_Vds=%2.4f' % (
Vds) + '.txt'
np.savetxt(os.path.join(spectra_fol, spectrum_file),
np.transpose(table))
print("Acquisition done.")
return locals()
def tidy_up(self):
self.end_saving()
print("Driving all voltages back to zero...")
self.sourceVds.set_voltage(0.)
self.sourceVg1.set_voltage(0.)
self.sourceVg2.set_voltage(0.)
class Measurement(MeasurementBase):
params = {
'Vgs': Sweep([0.]),
'Vg0': 0.,
'Vchuck0': 10.,
'Vchuckmax': 30.,
'CapaRatio': 10.,
'Rg': 100e3,
'stabilise_time': 0.3,
'comment': String(''),
'data_dir': Folder(r''),
'use_vna': Boolean(True),
'init_bilt': Boolean(False),
'init_yoko': Boolean(False)
}
observables = ['Vg', 'Vgm', 'Vchuck', 'Ileak']
alarms = [
['np.abs(Ileak) > 1e-8', MeasurementBase.ALARM_CALLCOPS]
]
def measure(self, data_dir, Vgs, Vg0, Vchuck0, Vchuckmax, CapaRatio, Rg,
comment, stabilise_time, use_vna, init_bilt, init_yoko,
**kwargs):
print("===================================")
print("Starting acquisition script...")
# initialise instruments
try:
print("Setting up DC sources and voltmeters...")
bilt = Bilt('TCPIP0::192.168.0.2::5025::SOCKET')
if init_bilt:
# source (bilt, channel, range, filter, slope in V/ms, label):
self.sourceVg = sourceVg = BiltVoltageSource(bilt, "I1", "12", "1", 0.005, "Vg")
else:
self.sourceVg = sourceVg = BiltVoltageSource(bilt, "I1", initialise=False)
# voltmeter (bilt, channel, filt, label=None)
self.meterVg = meterVg = BiltVoltMeter(bilt, "I5;C1", "2", "Vgm")
# voltage source for chuck
self.yoko = yoko = Yoko7651("GPIB::3::INSTR", func="VOLT",
rang=30., slope=1.,
initialise=init_yoko, verbose=True)
print("DC sources and voltmeters are set up.")
except:
print("There has been an error setting up DC sources and voltmeters:")
raise
try:
print("Setting up VNA...")
vna = AnritsuVNA('GPIB::6::INSTR')
sweeptime = vna.get_sweep_time()
print("VNA is set up.")
except:
print("There has been an error setting up the VNA:")
raise
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
# prepare saving DC data
filename = timestamp + ('_'+comment if comment else '')
self.prepare_saving(os.path.join(data_dir, filename+'.txt'))
if use_vna:
# prepare saving RF data
spectra_fol = os.path.join(data_dir, filename)
try:
os.makedirs(spectra_fol)
except OSError as e:
if e.errno != errno.EEXIST:
raise
if vna.get_sweep_type() == 'FSEGM':
with open(os.path.join(spectra_fol, 'VNAconfig'), 'w') as f:
vna.dump_freq_segments(f)
for Vg in Vgs:
if self.flags['quit_requested']:
print("Stopping acquisition.")
return locals()
print("Setting Vg = {}".format(Vg))
# calculate new chuck voltage to keep field constant
# set Vg
sourceVg.set_voltage(Vg)
Vchuck = Vchuck0+CapaRatio*(Vg-Vg0)
if np.abs(Vchuck) <= Vchuckmax:
print("Set chuck voltage:", Vchuck)
yoko.set_voltage(Vchuck)
else:
print("Chuck voltage too high:", Vchuck)
print("Not changing chuck voltage.")
Vchuck = yoko.get_voltage()
# wait
time.sleep(stabilise_time)
# read voltages
Vgm = meterVg.get_voltage()
# do calculations
Ileak = (Vg-Vgm)/Rg
# save DC data
self.save_row(locals())
if use_vna:
# save VNA data
print("Getting VNA spectra...")
vna.single_sweep(wait=False)
# display sweep progress
progressbar_wait(sweeptime)
# make sure sweep is really done
while not vna.is_sweep_done():
time.sleep(0.5)
table = vna.get_table([1,2,3,4])
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
spectrum_file = timestamp+'_Vg=%2.4f_Vchuck=%2.4f'%(Vg, Vchuck)+'.txt'
np.savetxt(os.path.join(spectra_fol, spectrum_file), np.transpose(table))
print("Acquisition done.")
return locals()
def tidy_up(self):
self.end_saving()
print("Driving all voltages back to zero...")
self.sourceVg.set_voltage(0.)
self.yoko.set_voltage(0.)
class Measurement(MeasurementBase):
params = {
'Vdss': Sweep([0.0]),
'Vg1s': Sweep([0.0]),
'Vg2s': Sweep([0.0]),
'commongate': Boolean(False),
'Rg1': 100e3,
'Rg2': 100e3,
'Rds': 22e3,
'stabilise_time': 0.05,
'comment': String(''),
'data_dir':
Folder(r'D:\MeasurementJANIS\Holger\KTW H5 2x3\2017-11-09 LHe')
}
observables = [
'Vg1', 'Vg1m', 'Ileak1', 'Vg2', 'Vg2m', 'Ileak2', 'Vds', 'Vdsm', 'Rs'
]
alarms = [
['np.abs(Ileak1) > 1e-8', MeasurementBase.ALARM_CALLCOPS],
['np.abs(Ileak2) > 1e-8', MeasurementBase.ALARM_CALLCOPS],
['np.abs(Vg1-Vg2)', MeasurementBase.ALARM_SHOWVALUE
] # useful if we just want to know how much voltage
# is applied between the two gates
]
def measure(self, data_dir, comment, Vdss, Vg1s, Vg2s, commongate, Rg1,
Rg2, Rds, stabilise_time, **kwargs):
print("===================================")
print("Starting acquisition script...")
# initialise instruments
try:
print("Setting up DC sources and voltmeters...")
bilt = Bilt('TCPIP0::192.168.0.2::5025::SOCKET')
self.sourceVds = sourceVds = BiltVoltageSource(bilt,
"I1",
initialise=False)
self.sourceVg1 = sourceVg1 = BiltVoltageSource(bilt,
"I2",
initialise=False)
self.sourceVg2 = sourceVg2 = BiltVoltageSource(bilt,
"I3",
initialise=False)
self.meterVds = meterVds = BiltVoltMeter(bilt, "I5;C1", "2",
"Vdsm")
self.meterVg1 = meterVg1 = BiltVoltMeter(bilt, "I5;C2", "2",
"Vg1m")
self.meterVg2 = meterVg2 = BiltVoltMeter(bilt, "I5;C3", "2",
"Vg2m")
print("DC sources and voltmeters are set up.")
except:
print(
"There has been an error setting up DC sources and voltmeters."
)
raise
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
# prepare saving data
filename = timestamp + '_' + (comment if comment else '') + '.txt'
self.prepare_saving(os.path.join(data_dir, filename))
# loops
for Vds in Vdss:
sourceVds.set_voltage(Vds)
for Vg2 in Vg2s:
if not commongate:
sourceVg2.set_voltage(Vg2)
for Vg1 in Vg1s:
if self.flags['quit_requested']:
return locals()
sourceVg1.set_voltage(Vg1)
if commongate:
Vg2 = Vg1
sourceVg2.set_voltage(Vg1)
# stabilise
time.sleep(stabilise_time)
# measure
Vdsm = meterVds.get_voltage()
Vg1m = meterVg1.get_voltage()
Vg2m = meterVg2.get_voltage()
# do calculations
Ileak1 = (Vg1 - Vg1m) / Rg1
Ileak2 = (Vg2 - Vg2m) / Rg2
Rs = Rds * Vdsm / (Vds - Vdsm)
# save data
self.save_row(locals())
print("Acquisition done.")
return locals()
def tidy_up(self):
self.end_saving()
print("Driving all voltages back to zero...")
self.sourceVds.set_voltage(0.)
self.sourceVg1.set_voltage(0.)
self.sourceVg2.set_voltage(0.)
class Measurement(MeasurementBase):
params = {
'sweep': Boolean(False),
'startpoint': 0.,
'direction': 1.,
'step': 1.,
'Ithresh': 3e-7,
'Vmax': 30,
'stabilise_time': 10,
'init': Boolean(True),
'use_vna': Boolean(True),
'comment': String(''),
'data_dir': Folder(r'D:\MeasurementJANIS\Holger\test')
}
observables = ['Vg', 'Vgm', 'Ileak']
alarms = []
def measure(self, step, startpoint, direction, Ithresh, Vmax, sweep,
stabilise_time, init, use_vna, data_dir, comment, **kwargs):
print("===================================")
print("Starting acquisition script...")
vna_string = ''
# initialise instruments
try:
print("----------------------------------------")
print("Setting up Keithley DC sources...")
self.sourceVg = sourceVg = K2400('GPIB::24::INSTR',
sourcemode='v',
vrang=200,
irang=10e-6,
slope=1,
initialise=init)
print("DC sources are set up.")
except:
print("There has been an error setting up DC sources.")
raise
if use_vna:
print("Setting up VNA...")
vna = AnritsuVNA('GPIB::6::INSTR')
sweeptime = vna.get_sweep_time()
if vna.get_sweep_type() != 'FSEGM':
raise Exception('Please use segmented frequency sweep')
# check if the RF power is the same on both ports and for all
# frequency segments
count = int(vna.query(':SENS:FSEGM:COUN?'))
vna_pow = None
for i in range(1, count + 1):
port1pow = float(
vna.query(':SENS:FSEGM{}:POW:PORT1?'.format(i)))
port2pow = float(
vna.query(':SENS:FSEGM{}:POW:PORT2?'.format(i)))
if vna_pow is None and port1pow == port2pow:
vna_pow = port1pow
elif vna_pow is not None and port1pow == port2pow and port1pow == vna_pow:
continue
else:
raise Exception(
"Please select the same power for all ports and frequency segments"
)
port1att = vna.get_source_att(1)
port2att = vna.get_source_att(2)
if port1att == port2att:
vna_pow -= port1att
else:
raise Exception(
"Please select the same attenuators for both ports")
vna_string = '_pwr={:.0f}'.format(vna_pow)
print("VNA is set up.")
# define name
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
filename = timestamp + vna_string + ('_' + comment if comment else '')
# prepare saving RF data
spectra_fol = os.path.join(data_dir, filename)
create_path(spectra_fol)
# prepare saving DC data
self.prepare_saving(os.path.join(data_dir, filename + '.txt'))
if use_vna:
# prepare saving RF data
spectra_fol = os.path.join(data_dir, filename)
create_path(spectra_fol)
# save segmented frequency sweep data to file
with open(os.path.join(spectra_fol, 'VNAconfig'), 'w') as f:
vna.dump_freq_segments(f)
Vg = startpoint
def measure_point(Ithresh=np.inf):
print('Setting Vg=' + str(Vg) + ' V...')
sourceVg.set_voltage(Vg)
print('Stabilising...')
progressbar_wait(stabilise_time)
# measure
Vgm = sourceVg.get_voltage()
Ileak = sourceVg.get_current()
# save data
self.save_row(locals())
# save VNA data
if use_vna:
# save VNA data
print("Getting VNA spectra...")
vna.single_sweep(wait=False)
# display sweep progress
progressbar_wait(sweeptime)
# make sure sweep is really done
while not vna.is_sweep_done():
time.sleep(0.5)
table = vna.get_table([1, 2, 3, 4])
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
spectrum_file = timestamp + '_Vg={:.3f}.txt'.format(Vg)
np.savetxt(os.path.join(spectra_fol, spectrum_file),
np.transpose(table))
return np.abs(Ileak) > Ithresh
# measure at 0 V
measure_point()
# sweep if requested
#╦direction = 1. # up
if direction not in [1., -1.]:
raise Exception("select valid direction 1. or -1.")
back_to_zero = False
decimals = int(max(1., -np.log10(step) + 1.))
while sweep:
if self.flags['quit_requested']:
return locals()
Vg = np.around(Vg + step * direction, decimals)
if np.abs(Vg) > Vmax:
print("Reached maximum voltage! Inverting sweep direction.")
if direction < 0. and Vg < 0.:
back_to_zero = True
direction = -direction
continue
leak = measure_point(Ithresh)
if leak:
if direction * Vg < 0.:
continue
if direction < 0. and Vg < 0.:
back_to_zero = True
direction = -direction
if np.abs(Vg) < 1e-12 and back_to_zero:
break
print("Acquisition done.")
return locals()
def tidy_up(self):
self.end_saving()
print("Driving all voltages back to zero...")
self.sourceVg.set_voltage(0.)