class IVExperiment(Experiment):
awg = Agilent33220A("192.168.5.198")
amplitude = FloatParameter(default=0.1, unit="V")
frequency = 167.0 # FloatParameter(default=167.0, unit="Hz")
sample_rate = 5e5
num_bursts = 10
preamp_gain = 1
r_ref = 1e3
current_input = OutputConnector(unit="V")
voltage_sample = OutputConnector(unit="V")
def init_streams(self):
descrip = DataStreamDescriptor()
descrip.data_name='current_input'
descrip.add_axis(DataAxis("time", np.arange(int(self.sample_rate*self.num_bursts/self.frequency))/self.sample_rate))
self.current_input.set_descriptor(descrip)
descrip = DataStreamDescriptor()
descrip.data_name='voltage_sample'
descrip.add_axis(DataAxis("time", np.arange(int(self.sample_rate*self.num_bursts/self.frequency))/self.sample_rate))
self.voltage_sample.set_descriptor(descrip)
def init_instruments(self):
# Configure the AWG
self.awg.output = False
self.awg.function = 'Sine'
self.awg.load_resistance = self.r_ref
self.awg.auto_range = True
self.awg.amplitude = self.amplitude.value # Preset to avoid danger
self.awg.dc_offset = 0.0
self.awg.frequency = self.frequency
self.awg.burst_state = True
self.awg.burst_cycles = self.num_bursts + 2
self.awg.trigger_source = "Bus"
self.awg.output = True
self.amplitude.assign_method(self.awg.set_amplitude)
# self.frequency.assign_method(self.awg.set_frequency)
# Setup the NIDAQ
max_voltage = 2.0 #self.amplitude.value*2.0
self.num_samples_total = int(self.sample_rate*(self.num_bursts+2)/self.frequency)
self.num_samples_trimmed = int(self.sample_rate*(self.num_bursts)/self.frequency)
self.trim_len = int(self.sample_rate/self.frequency)
self.analog_input = Task()
self.read = int32()
self.analog_input.CreateAIVoltageChan("Dev1/ai0", "", DAQmx_Val_Diff,
-max_voltage, max_voltage, DAQmx_Val_Volts, None)
self.analog_input.CreateAIVoltageChan("Dev1/ai1", "", DAQmx_Val_Diff,
-max_voltage, max_voltage, DAQmx_Val_Volts, None)
self.analog_input.CfgSampClkTiming("", self.sample_rate, DAQmx_Val_Rising,
DAQmx_Val_FiniteSamps , self.num_samples_total)
self.analog_input.CfgInputBuffer(2*self.num_samples_total)
self.analog_input.CfgDigEdgeStartTrig("/Dev1/PFI0", DAQmx_Val_Rising)
self.analog_input.StartTask()
# self.analog_input.SetStartTrigRetriggerable(1)
def shutdown_instruments(self):
self.awg.output = False
# self.awg.auto_range = True
try:
self.analog_input.StopTask()
self.analog_input.ClearTask()
except Exception as e:
logger.warning("Failed to clear DAQ task!")
async def run(self):
"""This is run for each step in a sweep."""
self.awg.trigger()
buf = np.empty(2*self.num_samples_total)
self.analog_input.ReadAnalogF64(self.num_samples_total, -1, DAQmx_Val_GroupByChannel,
buf, 2*self.num_samples_total, byref(self.read), None)
await self.current_input.push(buf[self.num_samples_total+self.trim_len:self.num_samples_total+self.trim_len+self.num_samples_trimmed]/self.r_ref)
await self.voltage_sample.push(buf[self.trim_len:self.trim_len+self.num_samples_trimmed]/self.preamp_gain)
await asyncio.sleep(0.02)
class nTronSwitchingExperiment(Experiment):
# Parameters
channel_bias = FloatParameter(default=0.05, unit="V") # On the 33220A
gate_bias = FloatParameter(default=0.0, unit="V") # On the M8190A
# Constants (set with attribute access if you want to change these!)
attempts = 1 << 8
samples = 384 #1024 + 16*20
measure_amplitude = 0.1
measure_duration = 250.0e-9
measure_frequency = 100e6
# arb
sample_rate = 12e9
repeat_time = 4 * 2.4e-6 # Picked very carefully for 100ns alignment
# Things coming back
voltage = OutputConnector()
# Instrument resources
arb = KeysightM8190A("192.168.5.108")
awg = Agilent33220A("192.168.5.198")
alz = AlazarATS9870("1")
def __init__(self, gate_amps, gate_durs):
self.gate_amps = gate_amps
self.gate_durs = gate_durs
super(nTronSwitchingExperiment, self).__init__()
def init_instruments(self):
self.awg.function = 'Pulse'
self.awg.frequency = 0.5e6
self.awg.pulse_width = 1e-6
self.awg.low_voltage = 0.0
self.awg.high_voltage = self.channel_bias.value
self.awg.burst_state = True
self.awg.burst_cycles = 1
self.awg.trigger_source = "External"
self.awg.output = True
self.ch = AlazarChannel({'channel': 1})
self.alz.add_channel(self.ch)
alz_cfg = {
'acquire_mode': 'digitizer',
'bandwidth': 'Full',
'clock_type': 'ref',
'delay': 850e-9,
'enabled': True,
'label': "Alazar",
'record_length': self.samples,
'nbr_segments': len(self.gate_amps) * len(self.gate_durs),
'nbr_waveforms': 1,
'nbr_round_robins': self.attempts,
'sampling_rate': 1e9,
'trigger_coupling': 'DC',
'trigger_level': 125,
'trigger_slope': 'rising',
'trigger_source': 'Ext',
'vertical_coupling': 'AC',
'vertical_offset': 0.0,
'vertical_scale': 0.1,
}
self.alz.set_all(alz_cfg)
self.loop.add_reader(self.alz.get_socket(self.ch),
self.alz.receive_data, self.ch, self.voltage)
self.arb.set_output(True, channel=2)
self.arb.set_output(True, channel=1)
self.arb.sample_freq = self.sample_rate
self.arb.set_waveform_output_mode("WSPEED", channel=1)
self.arb.set_waveform_output_mode("WSPEED", channel=2)
self.arb.set_output_route("DC", channel=1)
self.arb.set_output_route("DC", channel=2)
self.arb.set_output_complement(False, channel=1)
self.arb.set_output_complement(False, channel=2)
self.arb.set_voltage_amplitude(1.0, channel=1)
self.arb.set_voltage_amplitude(1.0, channel=2)
self.arb.continuous_mode = False
self.arb.gate_mode = False
self.arb.set_marker_level_low(0.0, channel=1, marker_type="sync")
self.arb.set_marker_level_high(1.5, channel=1, marker_type="sync")
self.arb.set_marker_level_low(0.0, channel=2, marker_type="sync")
self.arb.set_marker_level_high(1.5, channel=2, marker_type="sync")
self.setup_arb(
) #self.gate_bias.value, self.gate_pulse_amplitude.value, self.gate_pulse_duration.value) # Sequencing goes here
def setup_arb(
self): #, gate_bias, gate_pulse_amplitude, gate_pulse_duration):
self.arb.abort()
self.arb.delete_all_waveforms()
self.arb.reset_sequence_table()
seg_ids_ch1 = []
seg_ids_ch2 = []
# For the measurements pulses along the channel
wf = measure_pulse(amplitude=self.measure_amplitude,
duration=self.measure_duration,
frequency=self.measure_frequency)
wf_data = KeysightM8190A.create_binary_wf_data(wf, sync_mkr=1)
seg_id = self.arb.define_waveform(len(wf_data), channel=1)
self.arb.upload_waveform(wf_data, seg_id, channel=1)
seg_ids_ch1.append(seg_id)
# Build in a delay between sequences
settle_pts = 640 * np.int(
np.ceil(self.repeat_time * self.sample_rate / 640))
# settle_pts2 = 640*np.ceil(8*2.4e-9 * self.sample_rate / 640)
scenario = Scenario()
seq = Sequence(sequence_loop_ct=self.attempts * len(self.gate_amps) *
len(self.gate_durs))
for si in seg_ids_ch1:
seq.add_waveform(si)
seq.add_idle(settle_pts, 0.0)
scenario.sequences.append(seq)
self.arb.upload_scenario(scenario, start_idx=0, channel=1)
for amp in self.gate_amps:
for dur in self.gate_durs:
# For the switching pulses along the gate
wf = switching_pulse(
amplitude=amp,
duration=dur) #self.gate_pulse_duration.value)
wf_data = KeysightM8190A.create_binary_wf_data(wf)
seg_id = self.arb.define_waveform(len(wf_data), channel=2)
self.arb.upload_waveform(wf_data, seg_id, channel=2)
seg_ids_ch2.append(seg_id)
scenario = Scenario()
seq = Sequence(sequence_loop_ct=self.attempts)
for si in seg_ids_ch2:
seq.add_waveform(si)
seq.add_idle(settle_pts, 0.0)
scenario.sequences.append(seq)
self.arb.upload_scenario(scenario, start_idx=0, channel=2)
self.arb.set_sequence_mode("SCENARIO", channel=1)
self.arb.set_scenario_advance_mode("SINGLE", channel=1)
self.arb.set_scenario_start_index(0, channel=1)
self.arb.set_sequence_mode("SCENARIO", channel=2)
self.arb.set_scenario_advance_mode("SINGLE", channel=2)
self.arb.set_scenario_start_index(0, channel=2)
self.arb.initiate(channel=1)
self.arb.initiate(channel=2)
self.arb.advance()
def init_streams(self):
# Baked in data axes
descrip = DataStreamDescriptor()
descrip.add_axis(DataAxis("time", 1e-9 * np.arange(self.samples)))
if len(self.gate_durs) > 1:
descrip.add_axis(DataAxis("gate_pulse_duration", self.gate_durs))
descrip.add_axis(DataAxis("gate_pulse_amplitude", self.gate_amps))
descrip.add_axis(DataAxis("attempt", range(self.attempts)))
self.voltage.set_descriptor(descrip)
async def run(self):
# self.arb.stop()
self.arb.set_scenario_start_index(0, channel=1)
self.arb.set_scenario_start_index(0, channel=2)
self.arb.advance()
await asyncio.sleep(0.3)
self.alz.acquire()
await asyncio.sleep(0.3)
self.arb.trigger()
await self.alz.wait_for_acquisition(10.0)
await asyncio.sleep(0.8)
self.alz.stop()
# Seemingly we need to give the filters some time to catch up here...
await asyncio.sleep(0.02)
logger.info("Stream has filled {} of {} points".format(
self.voltage.points_taken, self.voltage.num_points()))
def shutdown_instruments(self):
self.awg.output = False
self.arb.stop()
self.loop.remove_reader(self.alz.get_socket(self.ch))
for name, instr in self._instruments.items():
instr.disconnect()
class ShortProcessSwitchingExperiment(Experiment):
# Parameters and outputs
pulse_duration = FloatParameter(default=5.0e-9, unit="s")
pulse_voltage = FloatParameter(default=1, unit="V")
bias_current = FloatParameter(default=60e-6, unit="A")
field = FloatParameter(default=0.0, unit="T")
voltage_chan = OutputConnector()
#voltage_MTJ = OutputConnector()
resistance_MTJ = OutputConnector()
# Constants (set with attribute access if you want to change these!)
attempts = 1 << 4
# MTJ measurements
measure_current = 3.0e-6
# Reference resistances and attenuations
matching_ref_res = 50
chan_bias_ref_res = 1e4
pspl_base_attenuation = 10
circuit_attenuation = 0
# Min/Max NIDAQ AI Voltage
min_daq_voltage = -1
max_daq_voltage = 1
# Measurement Sequence timing, clocks in Hz times in seconds
ai_clock = 0.25e6
do_clock = 1e5
run_time = 2e-4
settle_time = 0.5*run_time
integration_time = 0.1*run_time
pspl_delay = 0.25*0.5*run_time
# Instrument resources, NIDAQ called via PyDAQmx
arb_cb = Agilent33220A("192.168.5.199") # Channel Bias
pspl = Picosecond10070A("GPIB0::24::INSTR") # Gate Pulse
atten = RFMDAttenuator("calibration/RFSA2113SB_HPD_20160901.csv") # Gate Amplitude control
lock = SR865("USB0::0xB506::0x2000::002638::INSTR") # Gate Amplitude control
keith = Keithley2400("GPIB0::25::INSTR")
mag = AMI430("192.168.5.109")
def init_instruments(self):
# Channel bias arb
self.arb_cb.output = False
self.arb_cb.load_resistance = (self.chan_bias_ref_res+self.matching_ref_res)
self.arb_cb.function = 'Pulse'
self.arb_cb.pulse_period = 0.99*self.run_time
self.arb_cb.pulse_width = self.run_time - self.settle_time
self.arb_cb.pulse_edge = 100e-9
self.arb_cb.low_voltage = 0.0
self.arb_cb.high_voltage = self.bias_current.value*(self.chan_bias_ref_res+self.matching_ref_res)
self.arb_cb.polarity = 1
self.arb_cb.burst_state = True
self.arb_cb.burst_cycles = 1
self.arb_cb.trigger_source = "External"
self.arb_cb.burst_mode = "Triggered"
self.arb_cb.output = True
# Setup the Keithley
self.keith.triad()
self.keith.conf_meas_res(res_range=1e5)
self.keith.conf_src_curr(comp_voltage=0.5, curr_range=1.0e-5)
self.keith.current = self.measure_current
# Setup the magnet
self.mag.ramp()
# Setup the NIDAQ tasks
DAQmxResetDevice("Dev1")
self.nidaq = CallbackTask(["Dev1/ai0"], asyncio.get_event_loop(), int(self.integration_time*self.ai_clock), self.attempts, [self.voltage_chan],
min_voltage=self.min_daq_voltage, max_voltage=self.max_daq_voltage, ai_clock=self.ai_clock)
self.nidaq.StartTask()
# Setup DO Triggers, P1:0 triggers AWG, P1:1 triggers PSPL and DAQ analog input
self.digital_output = Task()
data_p0 = np.zeros(int(self.do_clock*self.run_time),dtype=np.uint8)
data_p0[0]=1
data_p1 = np.zeros(int(self.do_clock*self.run_time),dtype=np.uint8)
data_p1[int(self.do_clock*(self.pspl_delay))]=1 # PSPL delay
data = np.hstack([data_p0,data_p1])
self.digital_output.CreateDOChan("/Dev1/port0/line0:1","",DAQmx_Val_ChanPerLine)
self.digital_output.CfgSampClkTiming("",self.do_clock, DAQmx_Val_Rising, DAQmx_Val_FiniteSamps, int(data.size/2)*self.attempts)
self.digital_output.WriteDigitalLines(int(self.do_clock*self.run_time),0,1,DAQmx_Val_GroupByChannel,data,None,None)
# Setup the PSPL
self.pspl.amplitude = 7.5*np.power(10, (-self.pspl_base_attenuation)/20.0)
self.pspl.trigger_source = "EXT"
self.pspl.trigger_level = 0.5
self.pspl.output = True
# Setup PSPL Attenuator Control
self.atten.set_supply_method(self.lock.set_ao2)
self.atten.set_control_method(self.lock.set_ao3)
def set_pulse_voltage(voltage, base_atten=self.pspl_base_attenuation):
# Calculate the voltage controller attenuator setting
amplitude = 7.5*np.power(10, -base_atten/20.0)
vc_atten = abs(20.0 * np.log10(abs(voltage)/7.5)) - base_atten - self.circuit_attenuation
if vc_atten <= self.atten.minimum_atten():
base_atten -= 1
if base_atten < 0:
logger.error("Voltage controlled attenuation {} under range, PSPL at Max. Decrease circuit attenuation.".format(vc_atten))
raise ValueError("Voltage controlled attenuation {} under range, PSPL at Max. Decrease circuit attenuation.".format(vc_atten))
set_pulse_voltage(voltage, base_atten=base_atten)
return
if self.atten.maximum_atten() < vc_atten:
base_atten += 1
if base_atten > 80:
logger.error("Voltage controlled attenuation {} over range, PSPL at Min. Increase circuit attenuation.".format(vc_atten))
raise ValueError("Voltage controlled attenuation {} over range, PSPL at Min. Increase circuit attenuation.".format(vc_atten))
set_pulse_voltage(voltage, base_atten=base_atten)
return
#print("PSPL Amplitude: {}, Attenuator: {}".format(amplitude,vc_atten))
self.atten.set_attenuation(vc_atten)
self.pspl.amplitude = self.arb_cb.polarity*abs(amplitude)
time.sleep(0.04)
def set_awg_current(current):
if 0 <= current:
self.arb_cb.polarity = 1
self.arb_cb.low_voltage = 0
self.arb_cb.high_voltage = current*self.chan_bias_ref_res
else :
self.arb_cb.polarity = -1
self.arb_cb.low_voltage = current*self.chan_bias_ref_res
self.arb_cb.high_voltage = 0
self.pspl.amplitude = self.arb_cb.polarity*abs(self.pspl.amplitude)
time.sleep(0.04)
# Assign Methods
self.bias_current.assign_method(set_awg_current)
self.pulse_duration.add_post_push_hook(lambda: time.sleep(0.1))
self.pulse_duration.assign_method(self.pspl.set_duration)
self.pulse_voltage.assign_method(set_pulse_voltage)
self.field.assign_method(self.mag.set_field)
def init_streams(self):
# Baked in data axes
descrip = DataStreamDescriptor()
descrip.data_name='voltage'
descrip.add_axis(DataAxis("sample", range(int(self.integration_time*self.ai_clock))))
descrip.add_axis(DataAxis("attempt", range(self.attempts)))
self.voltage_chan.set_descriptor(descrip)
# descrip = DataStreamDescriptor()
# descrip.data_name='voltage'
# descrip.add_axis(DataAxis("sample", range(int(self.integration_time*self.ai_clock))))
# descrip.add_axis(DataAxis("attempt", range(self.attempts)))
# self.voltage_MTJ.set_descriptor(descrip)
descrip = DataStreamDescriptor()
descrip.data_name='resistance'
self.resistance_MTJ.set_descriptor(descrip)
async def run(self):
self.digital_output.StartTask()
self.digital_output.WaitUntilTaskDone(2*self.attempts*self.run_time)
self.digital_output.StopTask()
await self.resistance_MTJ.push(self.keith.resistance)
await asyncio.sleep(0.05)
# print("\t now ", self.nidaq.points_read)
# logger.debug("Stream has filled {} of {} points".format(self.voltage.points_taken, self.voltage.num_points() ))
def shutdown_instruments(self):
self.keith.current = 0.0e-5
self.mag.zero()
try:
for ch in [self.nidaq, self.nidaq_MTJ]:
ch.StopTask()
ch.ClearTask()
self.digital_output.StopTask()
del ch
except Exception as e:
print("Warning: failed to stop task (this normally happens with no consequences when taking multiple samples per trigger).")
pass
self.arb_cb.output = False
self.pspl.output = False
for name, instr in self._instruments.items():
instr.disconnect()
class nTronSwitchingExperimentFast(Experiment):
# Parameters and outputs
# channel_bias = FloatParameter(default=100e-6, unit="A") # On the 33220A
pulse_duration = FloatParameter(default=5.0e-9, unit="s")
pulse_voltage = FloatParameter(default=1, unit="V")
channel_bias = FloatParameter(default=500e-6, unit="A")
voltage = OutputConnector()
# Constants (set with attribute access if you want to change these!)
attempts = 1 << 6
# Reference resistances and attenuations
matching_ref_res = 50
chan_bias_ref_res = 1e4
pspl_base_attenuation = 10
circuit_attenuation = 0
pulse_polarity = 1
# Min/Max NIDAQ AI Voltage
min_daq_voltage = 0
max_daq_voltage = 10
# Measurement Sequence timing, clocks in Hz times in seconds
ai_clock = 0.25e6
do_clock = 0.5e6
trig_interval = 0.2e-3 # The repetition rate for switching attempts
bias_pulse_width = 40e-6 # This is how long the bias pulse is
pspl_trig_time = 4e-6 # When we trigger the gate pulse
integration_time = 20e-6 # How long to measure for
ai_delay = 2e-6 # How long before the measurement begins
# Instrument resources, NIDAQ called via PyDAQmx
arb_cb = Agilent33220A("192.168.5.199") # Channel Bias
pspl = Picosecond10070A("GPIB0::24::INSTR") # Gate Pulse
atten = RFMDAttenuator(
"calibration/RFSA2113SB_HPD_20160901.csv") # Gate Amplitude control
lock = SR865(
"USB0::0xB506::0x2000::002638::INSTR") # Gate Amplitude control
def init_instruments(self):
# Channel bias arb
self.arb_cb.output = False
self.arb_cb.load_resistance = (self.chan_bias_ref_res +
self.matching_ref_res)
self.arb_cb.function = 'Pulse'
self.arb_cb.pulse_period = 0.99 * self.trig_interval # Slightly under the trig interval since we are driving with another instrument
self.arb_cb.pulse_width = self.bias_pulse_width
self.arb_cb.pulse_edge = 100e-9 # Going through the DC port of a bias-tee, no need for fast edges
self.arb_cb.low_voltage = 0.0
self.arb_cb.high_voltage = self.channel_bias.value * (
self.chan_bias_ref_res + self.matching_ref_res)
self.arb_cb.burst_state = True
self.arb_cb.burst_cycles = 1
self.arb_cb.trigger_source = "External"
self.arb_cb.burst_mode = "Triggered"
self.arb_cb.output = True
self.arb_cb.polarity = 1
# Setup the NIDAQ
DAQmxResetDevice("Dev1")
measure_points = int(self.integration_time * self.ai_clock)
self.nidaq = CallbackTask(
asyncio.get_event_loop(),
measure_points,
self.attempts,
self.voltage,
# chunk_size=measure_points*(self.attempts>>2),
min_voltage=self.min_daq_voltage,
max_voltage=self.max_daq_voltage,
ai_clock=self.ai_clock)
self.nidaq.StartTask()
# Setup DO Triggers, P1:0 triggers AWG, P1:1 triggers PSPL and DAQ analog input
self.digital_output = Task()
data_p0 = np.zeros(int(self.do_clock * self.trig_interval),
dtype=np.uint8)
data_p0[0] = 1
data_p1 = np.zeros(int(self.do_clock * self.trig_interval),
dtype=np.uint8)
data_p1[int(self.do_clock * (self.pspl_trig_time))] = 1
data = np.append(data_p0, data_p1)
self.digital_output.CreateDOChan("/Dev1/port0/line0:1", "",
DAQmx_Val_ChanPerLine)
self.digital_output.CfgSampClkTiming(
"", self.do_clock, DAQmx_Val_Rising, DAQmx_Val_FiniteSamps,
int(data.size / 2) * self.attempts)
self.digital_output.WriteDigitalLines(
int(self.do_clock * self.trig_interval), 0, 1,
DAQmx_Val_GroupByChannel, data, None, None)
# Setup the PSPL`
self.pspl.amplitude = 7.5 * np.power(
10, (-self.pspl_base_attenuation) / 20.0)
self.pspl.trigger_source = "EXT"
self.pspl.trigger_level = 0.5
self.pspl.output = True
# Setup PSPL Attenuator Control
self.atten.set_supply_method(self.lock.set_ao2)
self.atten.set_control_method(self.lock.set_ao3)
# Setup bias current method
def set_bias(value):
self.arb_cb.high_voltage = self.channel_bias.value * (
self.chan_bias_ref_res + self.matching_ref_res)
self.arb_cb.low_voltage = 0.0
self.channel_bias.assign_method(set_bias)
def set_voltage(voltage, base_atten=self.pspl_base_attenuation):
# Calculate the voltage controller attenuator setting
amplitude = 7.5 * np.power(10, -base_atten / 20.0)
vc_atten = abs(20.0 * np.log10(
abs(voltage) / 7.5)) - base_atten - self.circuit_attenuation
if vc_atten <= self.atten.minimum_atten():
base_atten -= 1
if base_atten < 0:
logger.error(
"Voltage controlled attenuation {} under range, PSPL at Max. Decrease circuit attenuation."
.format(vc_atten))
raise ValueError(
"Voltage controlled attenuation {} under range, PSPL at Max. Decrease circuit attenuation."
.format(vc_atten))
set_voltage(voltage, base_atten=base_atten)
return
if self.atten.maximum_atten() < vc_atten:
base_atten += 1
if base_atten > 80:
logger.error(
"Voltage controlled attenuation {} over range, PSPL at Min. Increase circuit attenuation."
.format(vc_atten))
raise ValueError(
"Voltage controlled attenuation {} over range, PSPL at Min. Increase circuit attenuation."
.format(vc_atten))
set_voltage(voltage, base_atten=base_atten)
return
#print("PSPL Amplitude: {}, Attenuator: {}".format(amplitude,vc_atten))
self.atten.set_attenuation(vc_atten)
self.pspl.amplitude = self.pulse_polarity * amplitude
time.sleep(0.04)
# Assign Methods
#self.channel_bias.assign_method(lambda i: self.arb_cb.set_high_voltage(i*self.chan_bias_ref_res))
self.pulse_duration.add_post_push_hook(lambda: time.sleep(0.1))
self.pulse_duration.assign_method(self.pspl.set_duration)
self.pulse_voltage.assign_method(set_voltage)
def init_streams(self):
# Baked in data axes
descrip = DataStreamDescriptor()
descrip.data_name = 'voltage'
descrip.add_axis(
DataAxis("sample",
range(int(self.integration_time * self.ai_clock))))
descrip.add_axis(DataAxis("attempt", range(self.attempts)))
self.voltage.set_descriptor(descrip)
async def run(self):
self.digital_output.StartTask()
self.digital_output.WaitUntilTaskDone(2 * self.attempts *
self.trig_interval)
self.digital_output.StopTask()
await asyncio.sleep(0.05)
# print("\t now ", self.nidaq.points_read)
logger.debug("Stream has filled {} of {} points".format(
self.voltage.points_taken, self.voltage.num_points()))
def shutdown_instruments(self):
try:
# self.analog_input.StopTask()
self.nidaq.StopTask()
self.nidaq.ClearTask()
self.digital_output.StopTask()
del self.nidaq
except Exception as e:
print(
"Warning: failed to stop task (this normally happens with no consequences when taking multiple samples per trigger)."
)
pass
self.arb_cb.output = False
self.pspl.output = False
for name, instr in self._instruments.items():
instr.disconnect()
class ShortProcessSwitchingExperimentReset(Experiment):
# Parameters and outputs
pulse_duration = FloatParameter(default=5.0e-9, unit="s")
pulse_voltage = FloatParameter(default=1, unit="V")
bias_current = FloatParameter(default=60e-6, unit="A")
field = FloatParameter(default=0.0, unit="T")
voltage = OutputConnector()
polarity = 1
attempts = 1 << 4 # How many times to try switching per set of conditions
measure_current = 10.0e-6 # MTJ sense current
reset_current = 0.5e-3 # AWG reset current (remember division)
MTJ_res = 100e3 # MTJ Resistance
# Reference resistances and attenuations
matching_ref_res = 50
chan_bias_ref_res = 1e4
reset_bias_ref_res = 5e3
pspl_base_attenuation = 10
circuit_attenuation = 0
# Reset Pulse Switching Pulse
# ___/\____
# \_______/ / \
# A B C D
# |------------------------------------->
# MEAS Begins (ignore middle) MEAS Ends
# | Integ. time| |integ time|
# Measurement Sequence timing, clocks in Hz times in seconds
ai_clock = 0.25e6
do_clock = 0.5e6
trig_interval = 200e-6 # The repetition rate for switching attempts
bias_pulse_width = 40e-6 # This is how long the bias pulse is
reset_pulse_width = 40e-6 # This is how long the reset pulse is
meas_duration = 140e-6 # This is how long the meas is
reset_trig_time = 0e-6 # (A) When we trigger the reset pulse
meas_trig_time = 50e-6 # (B) When the measurement trigger begins
switch_trig_time = 4e-6 # (C) When we trigger the reset pulse
pspl_trig_time = 4e-6 # (D) When we trigger the gate pulse
integration_time = 20e-6 # How long to measure for at the beginning and end
# Instrument resources, NIDAQ called via PyDAQmx
arb_cb = Agilent33220A("192.168.5.199") # Channel Bias
arb_reset = Agilent33220A("192.168.5.198") # Channel reset pulses
pspl = Picosecond10070A("GPIB0::24::INSTR") # Gate Pulse
atten = RFMDAttenuator("calibration/RFSA2113SB_HPD_20160901.csv") # Gate Amplitude control
lock = SR865("USB0::0xB506::0x2000::002638::INSTR") # Gate Amplitude control
keith = Keithley2400("GPIB0::25::INSTR")
mag = AMI430("192.168.5.109")
def init_instruments(self):
# Channel bias arb
self.arb_cb.output = False
self.arb_cb.load_resistance = (self.chan_bias_ref_res+self.matching_ref_res)
self.arb_cb.function = 'Pulse'
self.arb_cb.pulse_period = 0.99*self.trig_interval
self.arb_cb.pulse_width = self.bias_pulse_width
self.arb_cb.pulse_edge = 100e-9
self.arb_cb.low_voltage = 0.0
self.arb_cb.high_voltage = self.bias_current.value*(self.chan_bias_ref_res+self.matching_ref_res)
self.arb_cb.polarity = self.polarity
self.arb_cb.burst_state = True
self.arb_cb.burst_cycles = 1
self.arb_cb.trigger_source = "External"
self.arb_cb.burst_mode = "Triggered"
self.arb_cb.output = True
# MTJ reset arb
self.arb_reset.output = False
self.arb_reset.load_resistance = (self.reset_bias_ref_res+self.matching_ref_res)
self.arb_reset.function = 'Pulse'
self.arb_reset.pulse_period = 0.99*self.trig_interval
self.arb_reset.pulse_width = self.reset_pulse_width
self.arb_reset.pulse_edge = 100e-9
self.arb_reset.low_voltage = 0.0
self.arb_reset.high_voltage = self.reset_current*(self.reset_bias_ref_res+self.matching_ref_res)
self.arb_reset.polarity = -self.polarity
self.arb_reset.burst_state = True
self.arb_reset.burst_cycles = 1
self.arb_reset.trigger_source = "External"
self.arb_reset.burst_mode = "Triggered"
self.arb_reset.output = True
# Setup the Keithley
self.keith.triad()
self.keith.conf_meas_res(res_range=1e5)
self.keith.conf_src_curr(comp_voltage=0.5, curr_range=1.0e-4)
self.keith.current = self.measure_current
# Setup the magnet
self.mag.ramp()
# Setup the NIDAQ tasks
DAQmxResetDevice("Dev1")
self.nidaq = CallbackTask(["Dev1/ai2"], asyncio.get_event_loop(), int(self.meas_duration*self.ai_clock), self.attempts, [self.voltage],
trigger="/Dev1/PFI12", min_voltage=-self.MTJ_res*self.measure_current, max_voltage=self.MTJ_res*self.measure_current,
ai_clock=self.ai_clock)
self.nidaq.StartTask()
self.digital_output = Task()
do_reset = np.zeros(int(self.do_clock*self.trig_interval),dtype=np.uint8)
do_reset[int(self.do_clock*self.reset_trig_time)]=1
do_bias = np.zeros(int(self.do_clock*self.trig_interval),dtype=np.uint8)
do_bias[int(self.do_clock*self.switch_trig_time)]=1
do_pspl = np.zeros(int(self.do_clock*self.trig_interval),dtype=np.uint8)
do_pspl[int(self.do_clock*self.pspl_trig_time)]=1
do_meas = np.zeros(int(self.do_clock*self.trig_interval),dtype=np.uint8)
do_meas[int(self.do_clock*self.meas_trig_time)]=1
data = np.hstack([do_reset, do_bias, do_pspl, do_meas])
self.digital_output.CreateDOChan("/Dev1/port0/line0:3","",DAQmx_Val_ChanPerLine)
self.digital_output.CfgSampClkTiming("",self.do_clock, DAQmx_Val_Rising, DAQmx_Val_FiniteSamps, int(data.size/4)*self.attempts)
self.digital_output.WriteDigitalLines(int(self.do_clock*self.trig_interval),0,1,DAQmx_Val_GroupByChannel,data,None,None)
# Setup the PSPL
self.pspl.amplitude = 7.5*np.power(10, (-self.pspl_base_attenuation)/20.0)
self.pspl.trigger_source = "EXT"
self.pspl.trigger_level = 0.5
self.pspl.output = True
# Setup PSPL Attenuator Control
self.atten.set_supply_method(self.lock.set_ao2)
self.atten.set_control_method(self.lock.set_ao3)
def set_pulse_voltage(voltage, base_atten=self.pspl_base_attenuation):
# Calculate the voltage controller attenuator setting
amplitude = 7.5*np.power(10, -base_atten/20.0)
vc_atten = abs(20.0 * np.log10(abs(voltage)/7.5)) - base_atten - self.circuit_attenuation
if vc_atten <= self.atten.minimum_atten():
base_atten -= 1
if base_atten < 0:
logger.error("Voltage controlled attenuation {} under range, PSPL at Max. Decrease circuit attenuation.".format(vc_atten))
raise ValueError("Voltage controlled attenuation {} under range, PSPL at Max. Decrease circuit attenuation.".format(vc_atten))
set_pulse_voltage(voltage, base_atten=base_atten)
return
if self.atten.maximum_atten() < vc_atten:
base_atten += 1
if base_atten > 80:
logger.error("Voltage controlled attenuation {} over range, PSPL at Min. Increase circuit attenuation.".format(vc_atten))
raise ValueError("Voltage controlled attenuation {} over range, PSPL at Min. Increase circuit attenuation.".format(vc_atten))
set_pulse_voltage(voltage, base_atten=base_atten)
return
#print("PSPL Amplitude: {}, Attenuator: {}".format(amplitude,vc_atten))
self.atten.set_attenuation(vc_atten)
self.pspl.amplitude = self.arb_cb.polarity*abs(amplitude)
time.sleep(0.04)
def set_awg_current(current):
if 0 <= current:
self.arb_cb.polarity = 1
self.arb_cb.low_voltage = 0
self.arb_cb.high_voltage = current*self.chan_bias_ref_res
else :
self.arb_cb.polarity = -1
self.arb_cb.low_voltage = current*self.chan_bias_ref_res
self.arb_cb.high_voltage = 0
self.pspl.amplitude = self.arb_cb.polarity*abs(self.pspl.amplitude)
time.sleep(0.04)
# Assign Methods
self.bias_current.assign_method(set_awg_current)
self.pulse_duration.assign_method(self.pspl.set_duration)
self.pulse_voltage.assign_method(set_pulse_voltage)
self.field.assign_method(self.mag.set_field)
self.pulse_duration.add_post_push_hook(lambda: time.sleep(0.05))
self.pulse_voltage.add_post_push_hook(lambda: time.sleep(0.05))
self.bias_current.add_post_push_hook(lambda: time.sleep(0.05))
def init_streams(self):
descrip = DataStreamDescriptor()
descrip.data_name='voltage'
descrip.add_axis(DataAxis("sample", range(int(self.meas_duration*self.ai_clock))))
descrip.add_axis(DataAxis("attempt", range(self.attempts)))
self.voltage.set_descriptor(descrip)
async def run(self):
self.digital_output.StartTask()
self.digital_output.WaitUntilTaskDone(2*self.attempts*self.trig_interval)
self.digital_output.StopTask()
await asyncio.sleep(0.05)
def shutdown_instruments(self):
self.keith.current = 0.0e-5
self.keith.triad(down=True)
self.mag.zero()
try:
for ch in [self.nidaq, self.nidaq_MTJ]:
ch.StopTask()
ch.ClearTask()
self.digital_output.StopTask()
del ch
except Exception as e:
print("Warning: failed to stop task (this normally happens with no consequences when taking multiple samples per trigger).")
pass
self.arb_cb.output = False
self.pspl.output = False
for name, instr in self._instruments.items():
instr.disconnect()