def add_AO_funcgen_channel(self,
ao,
name=None,
func=None,
fsamp=None,
amp=None,
offset='0V'):
""" Adds an analog output funcgen channel (or channels) to the task """
ao_name = "{}/ao{}".format(self.dev.name, ao).encode('ascii')
ch_name = 'ao{}'.format(ao) if name is None else name
ch_name = ch_name.encode('ascii')
self.AOs.append(ch_name)
if fsamp is None or amp is None:
raise Exception("Must include fsamp, and amp")
fsamp_mag = float(Q_(fsamp).to('Hz').magnitude)
amp_mag = float(Q_(amp).to('V').magnitude)
off_mag = float(Q_(offset).to('V').magnitude)
func_map = {
'sin': mx.DAQmx_Val_Sine,
'tri': mx.DAQmx_Val_Triangle,
'squ': mx.DAQmx_Val_Square,
'saw': mx.DAQmx_Val_Sawtooth
}
func = func_map[func]
self.t.CreateAOFuncGenChan(ao_name, ch_name, func, fsamp_mag, amp_mag,
off_mag)
def read_AI_scalar(self, timeout=-1.0):
if timeout != -1.0:
timeout = float(Q_(timeout).to('s').magnitude)
value = c_double()
self.t.ReadAnalogScalarF64(timeout, byref(value), None)
return Q_(value.value, 'V')
def read_AI_channels(self, samples=-1, timeout=-1.0):
""" Returns a dict containing the AI buffers. """
samples = int(samples)
if timeout != -1.0:
timeout = float(Q_(timeout).to('s').magnitude)
if samples == -1:
buf_size = self.get_buf_size() * len(self.AIs)
else:
buf_size = samples * len(self.AIs)
data = np.zeros(buf_size, dtype=np.float64)
num_samples_read = c_int32()
self.t.ReadAnalogF64(samples, timeout, mx.DAQmx_Val_GroupByChannel,
data, len(data), byref(num_samples_read), None)
num_samples_read = num_samples_read.value
res = {}
for i, ch_name in enumerate(self.AIs):
start = i * num_samples_read
stop = (i + 1) * num_samples_read
res[ch_name] = Q_(data[start:stop], 'V')
res['t'] = Q_(
np.linspace(0,
num_samples_read / self.fsamp,
num_samples_read,
endpoint=False), 's')
return res
def take_measure(COUNTER, POWERMETER, Vthresh, integration_time):
'''
Collect counts during integration_time and measures power
Input Parameters:
COUNTER: frequency counter object
POWERMETER: powermeter object
Vthres: threshold voltage for frequency counter
Returns: (cps, int_power)
cps: counts per second
power: average optical power during measurement returned as pint.Measurement object
'''
with visa_timeout_context(COUNTER._rsrc, 60000): # timeout of 60,000 msec
COUNTER.Vthreshold = Q_(Vthresh, 'V')
COUNTER.write('INIT') # Initiate couting
COUNTER.write('*WAI')
if POWERMETER is not None:
power = POWERMETER.measure(n_samples=int(
integration_time / 0.003)) # each sample about 3ms
else:
power = Q_(0.0, 'W').plus_minus(Q_(0.0, 'W'))
num_counts = float(COUNTER.query('FETC?'))
cps = num_counts / integration_time
return (cps, power)
def _handle_minmax_AO(self, min_val, max_val):
if min_val is None or max_val is None:
min_mag, max_mag = self.dev.get_AO_max_range()
else:
min_mag = Q_(min_val).to('V').magnitude
max_mag = Q_(max_val).to('V').magnitude
return min_mag, max_mag
def write_sequence(self,
data,
duration=None,
reps=None,
fsamp=None,
freq=None,
onboard=True):
"""Write an array of samples to the digital output channel
Outputs a buffered digital waveform, writing each value in sequence at
the rate determined by `duration` and `fsamp` or `freq`. You must
specify either `fsamp` or `freq`.
This function blocks until the output sequence has completed.
Parameters
----------
data : array or list of ints or bools
The sequence of samples to output. For a single-line DO channel,
samples can be bools.
duration : Quantity, optional
How long the entirety of the output lasts, specified as a
second-compatible Quantity. If `duration` is longer than a single
period of data, the waveform will repeat. Use either this or
`reps`, not both. If neither is given, waveform is output once.
reps : int or float, optional
How many times the waveform is repeated. Use either this or
`duration`, not both. If neither is given, waveform is output once.
fsamp: Quantity, optional
This is the sample frequency, specified as a Hz-compatible
Quantity. Use either this or `freq`, not both.
freq : Quantity, optional
This is the frequency of the *overall waveform*, specified as a
Hz-compatible Quantity. Use either this or `fsamp`, not both.
onboard : bool, optional
Use only onboard memory. Defaults to True. If False, all data will
be continually buffered from the PC memory, even if it is only
repeating a small number of samples many times.
"""
if (fsamp is None) == (freq is None):
raise Exception("Need one and only one of 'fsamp' or 'freq'")
if fsamp is None:
fsamp = Q_(freq) * len(data)
else:
fsamp = Q_(fsamp)
if (duration is not None) and (reps is not None):
raise Exception(
"Can use at most one of `duration` or `reps`, not both")
if duration is None:
duration = (reps or 1) * len(data) / fsamp
fsamp, n_samples = _handle_timing_params(duration, fsamp, len(data))
with self.dev.create_task() as t:
t.add_DO_channel(self._get_name())
t.set_DO_only_onboard_mem(self._get_name(), onboard)
t.config_timing(fsamp, n_samples, clock='')
t.write_DO_channels({self.name: data}, [self])
t.t.WaitUntilTaskDone(-1)
def set_low(self, low, channel=1):
""" Set the low voltage level of the current waveform.
This changes the low level while keeping the high level fixed.
Parameters
----------
low : pint.Quantity
The new low level in volt-compatible units
"""
low = Q_(low)
mag = low.to('V').magnitude
self.inst.write('source{}:voltage:low {}V'.format(channel, mag))
def set_offset(self, offset, channel=1):
""" Set the voltage offset of the current waveform.
This changes the offset while keeping the amplitude fixed.
Parameters
----------
offset : pint.Quantity
The new voltage offset in volt-compatible units
"""
offset = Q_(offset)
mag = offset.to('V').magnitude
self.inst.write('source{}:voltage:offset {}V'.format(channel, mag))
def bring_down_from_breakdown(SOURCEMETER, Vbd):
Vstep = Q_(5.0, 'V')
Vinit = Vbd - Vstep
while (Vinit > Q_(0, 'V')):
# SOURCEMETER.write(':SOUR1:VOLT {}'.format(Vinit))
# SOURCEMETER.write(':OUTP ON')
SOURCEMETER.set_voltage(Vinit)
Vinit = Vinit - Vstep
time.sleep(0.5)
SOURCEMETER.set_voltage(Q_(0, 'V'))
print('Sourcemeter at 0V')
def _handle_timing_params(duration, fsamp, n_samples):
if duration:
duration = Q_(duration).to('s')
if fsamp:
fsamp = Q_(fsamp).to('Hz')
n_samples = int((duration*fsamp).to('')) # Exclude endpoint
else:
n_samples = int(n_samples or 1000.)
fsamp = n_samples / duration
elif fsamp:
fsamp = Q_(fsamp).to('Hz')
n_samples = int(n_samples or 1000.)
return fsamp, n_samples
def set_high(self, high, channel=1):
""" Set the high voltage level of the current waveform.
This changes the high level while keeping the low level fixed.
Parameters
----------
high : pint.Quantity
The new high level in volt-compatible units
"""
high = Q_(high)
mag = high.to('V').magnitude
self.inst.write('source{}:voltage:high {}V'.format(channel, mag))
def output_pulses(self,
freq,
duration=None,
reps=None,
idle_high=False,
delay=None,
duty_cycle=0.5):
"""Generate digital pulses using the counter.
Outputs digital pulses with a given frequency and duty cycle.
This function blocks until the output sequence has completed.
Parameters
----------
freq : Quantity
This is the frequency of the pulses, specified as a Hz-compatible Quantity.
duration : Quantity, optional
How long the entirety of the output lasts, specified as a second-compatible
Quantity. Use either this or `reps`, not both. If neither is given, only one pulse is
generated.
reps : int, optional
How many pulses to generate. Use either this or `duration`, not both. If neither is
given, only one pulse is generated.
idle_high : bool, optional
Whether the resting state is considered high or low. Idles low by default.
delay : Quantity, optional
How long to wait before generating the first pulse, specified as a second-compatible
Quantity. Defaults to zero.
duty_cycle : float, optional
The width of the pulse divided by the pulse period. The default is a 50% duty cycle.
"""
idle_state = mx.High if idle_high else mx.Low
delay = 0 if delay is None else Q_(delay).to('s').magnitude
freq = Q_(freq).to('Hz').magnitude
if (duration is not None) and (reps is not None):
raise Exception(
"Can use at most one of `duration` or `reps`, not both")
if reps is None:
if duration is None:
reps = 1
else:
reps = int(Q_(duration).to('s').magnitude * freq)
with self.dev.create_task() as t:
t.t.CreateCOPulseChanFreq(self.fullname, None, mx.Hz, idle_state,
delay, freq, duty_cycle)
t.t.CfgImplicitTiming(mx.FiniteSamps, reps)
t.t.StartTask()
t.t.WaitUntilTaskDone(-1)
def set_phase(self, phase, channel=1):
""" Set the phase offset of the current waveform.
Parameters
----------
phase : pint.Quantity or number
The new low level in radian-compatible units. Unitless numbers are
treated as radians.
"""
phase = Q_(phase) # This also accepts dimensionless numbers as rads
if phase < -u.pi or phase > +u.pi:
raise Exception("Phase out of range. Must be between -pi and +pi")
mag = phase.to('rad').magnitude
self.inst.write('source{}:phase {}rad'.format(channel, mag))
def bring_to_breakdown(SOURCEMETER, Vbd):
Vinit = Q_(0, 'V')
Vstep = Q_(5.0, 'V')
while (Vinit < Vbd):
# SOURCEMETER.write(':SOUR1:VOLT {}'.format(Vinit))
# SOURCEMETER.write(':OUTP ON')
SOURCEMETER.set_voltage(Vinit)
Vinit = Vinit + Vstep
time.sleep(0.5)
SOURCEMETER.set_voltage(Vbd)
time.sleep(5.0)
print('Sourcemeter at breakdown voltage {}'.format(Vbd))
def sweep_end_frequency(self, val=None):
"""
Sets the end frequency of a sweep.
Sets the ending frequency for subsequent sweeps. If no value
is specified, the current ending frequency setting is returned.
Parameters
----------
val : float, optional
The ending value of the frequency sweep in THz.
Step: 0.00001 (THz)
Returns
-------
Quantity
The current sweep end frequency in THz, and its units.
>>> laser.sweep_end_frequency()
<Quantity(183.92175, 'terahertz')>
>>> laser.sweep_end_frequency(185.5447)
<Quantity(185.5447, 'terahertz')>
"""
return Q_(float(self._set_var("FF", 5, val)), 'THz')
def sweep_end_wavelength(self, val=None):
"""
Sets the end wavelength of a sweep.
Sets the ending wavelength for subsequent sweeps. If no value
is specified, the current ending wavelength setting is returned.
Parameters
----------
val : float, optional
The ending value of the wavelength sweep in nanometers.
Step: 0.0001 (nm)
Returns
-------
Quantity
The current sweep end wavelength in nm, and its units.
>>> laser.sweep_end_wavelength()
<Quantity(1630.0, 'nanometer')>
>>> laser.sweep_end_wavelength(1618)
<Quantity(1618.0, 'nanometer')>
"""
return Q_(float(self._set_var("SE", 4, val)), 'nm')
def test():
ps = MyPowerSupply()
ps.voltage = '12V'
assert ps.voltage == Q_(12, 'volts')
with pytest.raises(DimensionalityError):
ps.voltage = '200 mA'
def sweep_start_frequency(self, val=None):
"""
Sets the start frequency of a sweep.
Sets the starting frequency for subsequent sweeps. If no value
is specified, the current starting frequency setting is returned.
Parameters
----------
val : float, optional
The starting value of the frequency sweep in terahertz.
Step: 0.00001 (THz)
Returns
-------
Quantity
The current sweep start frequency in THz, and its units.
>>> laser.sweep_start_frequency()
<Quantity(199.86164, 'terahertz')>
>>> laser.sweep_start_frequency(196)
<Quantity(195.99999, 'terahertz')>
"""
return Q_(float(self._set_var("FS", 5, val)), 'THz')
def wavelength(self, val=None):
"""
Sets the output wavelength. If a value is not specified, returns the currently set wavelength.
Parameters
----------
val : float, optional
The wavelength the laser will be set to in nanometers.
Step: 0.0001 (nm)
Returns
-------
Quantity
The currently set wavelength in nanometers, and its units.
You can get the current wavelength by calling without arguments.
>>> laser.wavelength()
<Quantity(1630.0, 'nanometer')>
The following sets the output wavelength to 1560.123 nanometers.
>>> laser.wavelength(1560.123)
<Quantity(1630.0, 'nanometer')> # Bug returns the last set wavelength
"""
return Q_(float(self._set_var("WA", 4, val)), 'nm')
def sweep_step_frequency(self, val=None):
"""
Set the size of each step in the stepwise sweep when constant
frequency intervals are enabled. If a new value is not
provided, the current one will be returned. Units: THz
Parameters
----------
val : float, optional
The step size of each step in the stepwise sweep in terahertz.
Range: 0.00002 - 19.76219 (THz)
Step: 0.00001 (THz)
Returns
-------
Quantity
The set step size in THz, and its units.
>>> laser.sweep_step_frequency()
<Quantity(0.1, 'terahertz')>
>>> laser.sweep_step_frequency(0.24)
<Quantity(0.24, 'terahertz')>
"""
return Q_(float(self._set_var("WF", 5, val)), 'THz')
def read_measurement_stats(self, num):
"""
Read the value and statistics of a measurement.
Parameters
----------
num : int
Number of the measurement to read from, from 1-4
Returns
-------
stats : dict
Dictionary of measurement statistics. Includes value, mean, stddev,
minimum, maximum, and nsamps.
"""
prefix = 'measurement:meas{}'.format(num)
if not self.are_measurement_stats_on():
raise Exception("Measurement statistics are turned off, "
"please turn them on.")
# Potential issue: If we query for all of these values in one command,
# are they guaranteed to be taken from the same statistical set?
# Perhaps we should stop_acquire(), then run_acquire()...
keys = ['value', 'mean', 'stddev', 'minimum', 'maximum']
res = self.inst.query(
prefix +
':value?;mean?;stddev?;minimum?;maximum?;units?').split(';')
units = res.pop(-1).strip('"')
stats = {k: Q_(rval + units) for k, rval in zip(keys, res)}
num_samples = int(self.inst.query('measurement:statistics:weighting?'))
stats['nsamps'] = num_samples
return stats
def write_AO_channels(self, data, timeout=-1.0, autostart=True):
if timeout != -1.0:
timeout = float(Q_(timeout).to('s').magnitude)
arr = np.concatenate([data[ao].to('V').magnitude for ao in self.AOs]).astype(np.float64)
samples = data.values()[0].magnitude.size
samples_written = c_int32()
self.t.WriteAnalogF64(samples, autostart, timeout,
mx.DAQmx_Val_GroupByChannel, arr,
byref(samples_written), None)
def _write_AO_channels(self, data):
task = self._mxtasks['AO']
ao_names = [name for (name, ch) in self.channels.items() if ch.type == 'AO']
arr = np.concatenate([Q_(data[ao]).to('V').magnitude for ao in ao_names])
arr = arr.astype(np.float64)
samples = data.values()[0].magnitude.size
samples_written = c_int32()
task.WriteAnalogF64(samples, False, -1.0,
mx.DAQmx_Val_GroupByChannel, arr,
byref(samples_written), None)
def config_analog_trigger(self,
source,
trig_level,
rising=True,
pretrig_samples=2):
source_name = self._handle_ai(source)
level_mag = float(Q_(trig_level).to('V').magnitude)
slope = mx.DAQmx_Val_RisingSlope if rising else mx.DAQmx_Val_FallingSlope
self.t.CfgAnlgEdgeStartTrig(source_name, slope, level_mag,
pretrig_samples)
def write_DO_channels(self, data, channels, timeout=-1.0, autostart=True):
if timeout != -1.0:
timeout = float(Q_(timeout).to('s').magnitude)
arr = self._make_DO_array(data, channels)
n_samples = arr.size
n_samples_written = c_int32()
self.t.WriteDigitalU32(n_samples, autostart, timeout,
mx.DAQmx_Val_GroupByChannel, arr,
byref(n_samples_written), None)
def _read_AI_channels(self):
""" Returns a dict containing the AI buffers. """
task = self._mxtasks['AI']
bufsize_per_chan = c_uint32()
task.GetBufInputBufSize(byref(bufsize_per_chan))
buf_size = bufsize_per_chan.value * len(self.AIs)
data = np.zeros(buf_size, dtype=np.float64)
num_samples_read = c_int32()
task.ReadAnalogF64(-1, -1.0, mx.DAQmx_Val_GroupByChannel,
data, len(data), byref(num_samples_read), None)
num_samples_read = num_samples_read.value
res = {}
for i, ch in enumerate(self.AIs):
start = i*num_samples_read
stop = (i+1)*num_samples_read
res[ch.name] = Q_(data[start:stop], 'V')
res['t'] = Q_(np.linspace(0, float(num_samples_read-1)/self.fsamp, num_samples_read), 's')
return res
def set_sweep_center(self, center, channel=1):
""" Set the sweep frequency center.
This sets the sweep center frequency while keeping the sweep frequency
span fixed. The start and stop frequencies will be changed.
Parameters
----------
center : pint.Quantity
The center frequency of the sweep in Hz-compatible units
"""
val = Q_(center).to('Hz').magnitude
self.inst.write('source{}:freq:center {}Hz'.format(channel, val))
def set_sweep_hold_time(self, time, channel=1):
""" Set the hold time of the sweep.
The hold time is the amount of time that the frequency is held constant
after reaching the stop frequency.
Parameters
----------
time : pint.Quantity
The hold time in second-compatible units
"""
val = Q_(time).to('s').magnitude
self.inst.write('source{}:sweep:htime {}s'.format(channel, val))
def set_am_depth(self, depth, channel=1):
""" Set depth of amplitude modulation.
Parameters
----------
depth : number
Depth of modulation in percent. Must be between 0.0% and 120.0%.
Has resolution of 0.1%.
"""
val = Q_(depth).magnitude
if not (0.0 <= val <= 120.0):
raise Exception("Depth must be between 0.0 and 120.0")
self.inst.write('source{}:am:depth {:.1f}pct'.format(channel, val))
def tune_SHG(lm,
wait=False,
n_temp_samples=10,
temp_timeout=30 * u.minute,
temp_max_err=Q_(0.05, u.degK)):
shg_data = load_newest_SHG_calibration()
poling_region = get_poling_region(lm)
if poling_region:
T_set = Q_(
np.asscalar(shg_data[poling_region]['phase_match_model'](lm)),
u.degC)
print('tuning SHG:')
print('\tpoling region: {}, LM={:2.4f}um'.format(
current_poling_region, LM_cov[current_poling_region].magnitude))
print('\tset temperature: {:4.1f}C'.format(T_set.magnitude))
if wait:
oc.set_temp_and_wait(T_set,
max_err=temp_max_err,
n_samples=n_temp_samples,
timeout=temp_timeout)
else:
oc.set_set_temp(T_set)
def _set_amplitude(self, val, units, channel):
val = Q_(val)
mag = val.to('V').magnitude
self.inst.write('source{}:voltage {}{}'.format(channel, mag, units))