1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628
|
#
# This file is part of the PyMeasure package.
#
# Copyright (c) 2013-2024 PyMeasure Developers
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
import logging
import time
from warnings import warn
import numpy as np
from pymeasure.instruments import Instrument, SCPIMixin
from pymeasure.instruments.validators import truncated_range, strict_discrete_set
from .buffer import KeithleyBuffer
# Setup logging
log = logging.getLogger(__name__)
log.addHandler(logging.NullHandler())
class Keithley2450(KeithleyBuffer, SCPIMixin, Instrument):
""" Represents the Keithley 2450 SourceMeter and provides a
high-level interface for interacting with the instrument.
.. code-block:: python
keithley = Keithley2450("GPIB::1")
keithley.apply_current() # Sets up to source current
keithley.source_current_range = 10e-3 # Sets the source current range to 10 mA
keithley.compliance_voltage = 10 # Sets the compliance voltage to 10 V
keithley.source_current = 0 # Sets the source current to 0 mA
keithley.enable_source() # Enables the source output
keithley.measure_voltage() # Sets up to measure voltage
keithley.ramp_to_current(5e-3) # Ramps the current to 5 mA
print(keithley.voltage) # Prints the voltage in Volts
keithley.shutdown() # Ramps the current to 0 mA and disables output
"""
def __init__(self, adapter, name="Keithley 2450 SourceMeter", **kwargs):
super().__init__(
adapter,
name,
**kwargs
)
source_mode = Instrument.control(
":SOUR:FUNC?", ":SOUR:FUNC %s",
""" A string property that controls the source mode, which can
take the values 'current' or 'voltage'. The convenience methods
:meth:`~.Keithley2450.apply_current` and :meth:`~.Keithley2450.apply_voltage`
can also be used. """,
validator=strict_discrete_set,
values={'current': 'CURR', 'voltage': 'VOLT'},
map_values=True
)
source_enabled = Instrument.measurement(
"OUTPUT?",
""" Reads a boolean value that is True if the source is enabled. """,
cast=bool
)
###############
# Current (A) #
###############
current = Instrument.measurement(
":READ?",
""" Reads the current in Amps, if configured for this reading.
"""
)
current_range = Instrument.control(
":SENS:CURR:RANG?", ":SENS:CURR:RANG:AUTO 0;:SENS:CURR:RANG %g",
""" A floating point property that controls the measurement current
range in Amps, which can take values between -1.05 and +1.05 A.
Auto-range is disabled when this property is set. """,
validator=truncated_range,
values=[-1.05, 1.05]
)
current_nplc = Instrument.control(
":SENS:CURR:NPLC?", ":SENS:CURR:NPLC %g",
""" A floating point property that controls the number of power line cycles
(NPLC) for the DC current measurements, which sets the integration period
and measurement speed. Takes values from 0.01 to 10, where 0.1, 1, and 10 are
Fast, Medium, and Slow respectively. """,
values=[0.01, 10]
)
compliance_current = Instrument.control(
":SOUR:VOLT:ILIM?", ":SOUR:VOLT:ILIM %g",
""" A floating point property that controls the compliance current
in Amps. """,
validator=truncated_range,
values=[-1.05, 1.05]
)
source_current = Instrument.control(
":SOUR:CURR?", ":SOUR:CURR:LEV %g",
""" A floating point property that controls the source current
in Amps. """
)
source_current_range = Instrument.control(
":SOUR:CURR:RANG?", ":SOUR:CURR:RANG:AUTO 0;:SOUR:CURR:RANG %g",
""" A floating point property that controls the source current
range in Amps, which can take values between -1.05 and +1.05 A.
Auto-range is disabled when this property is set. """,
validator=truncated_range,
values=[-1.05, 1.05]
)
source_current_delay = Instrument.control(
":SOUR:CURR:DEL?", ":SOUR:CURR:DEL %g",
""" A floating point property that sets a manual delay for the source
after the output is turned on before a measurement is taken. When this
property is set, the auto delay is turned off. Valid values are
between 0 [seconds] and 999.9999 [seconds].""",
validator=truncated_range,
values=[0, 999.9999],
)
source_current_delay_auto = Instrument.control(
":SOUR:CURR:DEL:AUTO?", ":SOUR:CURR:DEL:AUTO %d",
""" A boolean property that enables or disables auto delay. Valid
values are True and False. """,
values={True: 1, False: 0},
map_values=True,
)
###############
# Voltage (V) #
###############
voltage = Instrument.measurement(
":READ?",
""" Reads the voltage in Volts, if configured for this reading.
"""
)
voltage_range = Instrument.control(
":SENS:VOLT:RANG?", ":SENS:VOLT:RANG:AUTO 0;:SENS:VOLT:RANG %g",
""" A floating point property that controls the measurement voltage
range in Volts, which can take values from -210 to 210 V.
Auto-range is disabled when this property is set. """,
validator=truncated_range,
values=[-210, 210]
)
voltage_nplc = Instrument.control(
":SENS:VOLT:NPLC?", ":SENS:VOLT:NPLC %g",
""" A floating point property that controls the number of power line cycles
(NPLC) for the DC voltage measurements, which sets the integration period
and measurement speed. Takes values from 0.01 to 10, where 0.1, 1, and 10 are
Fast, Medium, and Slow respectively. """
)
compliance_voltage = Instrument.control(
":SOUR:CURR:VLIM?", ":SOUR:CURR:VLIM %g",
""" A floating point property that controls the compliance voltage
in Volts. """,
validator=truncated_range,
values=[-210, 210]
)
source_voltage = Instrument.control(
":SOUR:VOLT?", ":SOUR:VOLT:LEV %g",
""" A floating point property that controls the source voltage
in Volts. """
)
source_voltage_range = Instrument.control(
":SOUR:VOLT:RANG?", ":SOUR:VOLT:RANG:AUTO 0;:SOUR:VOLT:RANG %g",
""" A floating point property that controls the source voltage
range in Volts, which can take values from -210 to 210 V.
Auto-range is disabled when this property is set. """,
validator=truncated_range,
values=[-210, 210]
)
source_voltage_delay = Instrument.control(
":SOUR:VOLT:DEL?", ":SOUR:VOLT:DEL %g",
""" A floating point property that sets a manual delay for the source
after the output is turned on before a measurement is taken. When this
property is set, the auto delay is turned off. Valid values are
between 0 [seconds] and 999.9999 [seconds].""",
validator=truncated_range,
values=[0, 999.9999],
)
source_voltage_delay_auto = Instrument.control(
":SOUR:VOLT:DEL:AUTO?", ":SOUR:VOLT:DEL:AUTO %d",
""" A boolean property that enables or disables auto delay. Valid
values are True and False. """,
values={True: 1, False: 0},
map_values=True,
)
####################
# Resistance (Ohm) #
####################
resistance = Instrument.measurement(
":READ?",
""" Reads the resistance in Ohms, if configured for this reading.
"""
)
resistance_range = Instrument.control(
":SENS:RES:RANG?", ":SENS:RES:RANG:AUTO 0;:SENS:RES:RANG %g",
""" A floating point property that controls the resistance range
in Ohms, which can take values from 0 to 210 MOhms.
Auto-range is disabled when this property is set. """,
validator=truncated_range,
values=[0, 210e6]
)
resistance_nplc = Instrument.control(
":SENS:RES:NPLC?", ":SENS:RES:NPLC %g",
""" A floating point property that controls the number of power line cycles
(NPLC) for the 2-wire resistance measurements, which sets the integration period
and measurement speed. Takes values from 0.01 to 10, where 0.1, 1, and 10 are
Fast, Medium, and Slow respectively. """
)
wires = Instrument.control(
":SENS:RES:RSENSE?", ":SENS:RES:RSENSE %d",
""" An integer property that controls the number of wires in
use for resistance measurements, which can take the value of
2 or 4.
""",
validator=strict_discrete_set,
values={4: 1, 2: 0},
map_values=True
)
buffer_points = Instrument.control(
":TRAC:POIN?", ":TRAC:POIN %d",
""" An integer property that controls the number of buffer points. This
does not represent actual points in the buffer, but the configuration
value instead. """,
validator=truncated_range,
values=[1, 6875000],
cast=int
)
means = Instrument.measurement(
":TRACe:STATistics:AVERage?",
""" Reads the calculated means (averages) for voltage,
current, and resistance from the buffer data as a list. """
)
maximums = Instrument.measurement(
":TRACe:STATistics:MAXimum?",
""" Returns the calculated maximums for voltage, current, and
resistance from the buffer data as a list. """
)
minimums = Instrument.measurement(
":TRACe:STATistics:MINimum?",
""" Returns the calculated minimums for voltage, current, and
resistance from the buffer data as a list. """
)
standard_devs = Instrument.measurement(
":TRACe:STATistics:STDDev?",
""" Returns the calculated standard deviations for voltage,
current, and resistance from the buffer data as a list. """
)
###########
# Filters #
###########
current_filter_type = Instrument.control(
":SENS:CURR:AVER:TCON?", ":SENS:CURR:AVER:TCON %s",
""" A String property that controls the filter's type for the current.
REP : Repeating filter
MOV : Moving filter""",
validator=strict_discrete_set,
values=['REP', 'MOV'],
map_values=False)
current_filter_count = Instrument.control(
":SENS:CURR:AVER:COUNT?", ":SENS:CURR:AVER:COUNT %d",
""" A integer property that controls the number of readings that are
acquired and stored in the filter buffer for the averaging""",
validator=truncated_range,
values=[1, 100],
cast=int)
current_filter_state = Instrument.control(
":SENS:CURR:AVER?", ":SENS:CURR:AVER %s",
""" A string property that controls if the filter is active.""",
validator=strict_discrete_set,
values=['ON', 'OFF'],
map_values=False)
voltage_filter_type = Instrument.control(
":SENS:VOLT:AVER:TCON?", ":SENS:VOLT:AVER:TCON %s",
""" A String property that controls the filter's type for the current.
REP : Repeating filter
MOV : Moving filter""",
validator=strict_discrete_set,
values=['REP', 'MOV'],
map_values=False)
voltage_filter_count = Instrument.control(
":SENS:VOLT:AVER:COUNT?", ":SENS:VOLT:AVER:COUNT %d",
""" A integer property that controls the number of readings that are
acquired and stored in the filter buffer for the averaging""",
validator=truncated_range,
values=[1, 100],
cast=int)
#####################
# Output subsystem #
#####################
current_output_off_state = Instrument.control(
":OUTP:CURR:SMOD?", ":OUTP:CURR:SMOD %s",
""" Select the output-off state of the SourceMeter.
HIMP : output relay is open, disconnects external circuitry.
NORM : V-Source is selected and set to 0V, Compliance is set to 0.5%
full scale of the present current range.
ZERO : V-Source is selected and set to 0V, compliance is set to the
programmed Source I value or to 0.5% full scale of the present current
range, whichever is greater.
GUAR : I-Source is selected and set to 0A""",
validator=strict_discrete_set,
values=['HIMP', 'NORM', 'ZERO', 'GUAR'],
map_values=False)
voltage_output_off_state = Instrument.control(
":OUTP:VOLT:SMOD?", ":OUTP:VOLT:SMOD %s",
""" Select the output-off state of the SourceMeter.
HIMP : output relay is open, disconnects external circuitry.
NORM : V-Source is selected and set to 0V, Compliance is set to 0.5%
full scale of the present current range.
ZERO : V-Source is selected and set to 0V, compliance is set to the
programmed Source I value or to 0.5% full scale of the present current
range, whichever is greater.
GUAR : I-Source is selected and set to 0A""",
validator=strict_discrete_set,
values=['HIMP', 'NORM', 'ZERO', 'GUAR'],
map_values=False)
####################
# Methods #
####################
def enable_source(self):
""" Enables the source of current or voltage depending on the
configuration of the instrument. """
self.write("OUTPUT ON")
def disable_source(self):
""" Disables the source of current or voltage depending on the
configuration of the instrument. """
self.write("OUTPUT OFF")
def measure_resistance(self, nplc=1, resistance=2.1e5, auto_range=True):
""" Configures the measurement of resistance.
:param nplc: Number of power line cycles (NPLC) from 0.01 to 10
:param resistance: Upper limit of resistance in Ohms, from -210 MOhms to 210 MOhms
:param auto_range: Enables auto_range if True, else uses the set resistance
"""
log.info("%s is measuring resistance.", self.name)
self.write(":SENS:FUNC 'RES';"
":SENS:RES:NPLC %f;" % nplc)
if auto_range:
self.write(":SENS:RES:RANG:AUTO 1;")
else:
self.resistance_range = resistance
self.check_errors()
def measure_voltage(self, nplc=1, voltage=21.0, auto_range=True):
""" Configures the measurement of voltage.
:param nplc: Number of power line cycles (NPLC) from 0.01 to 10
:param voltage: Upper limit of voltage in Volts, from -210 V to 210 V
:param auto_range: Enables auto_range if True, else uses the set voltage
"""
log.info("%s is measuring voltage.", self.name)
self.write(":SENS:FUNC 'VOLT';"
":SENS:VOLT:NPLC %f;" % nplc)
if auto_range:
self.write(":SENS:VOLT:RANG:AUTO 1;")
else:
self.voltage_range = voltage
self.check_errors()
def measure_current(self, nplc=1, current=1.05e-4, auto_range=True):
""" Configures the measurement of current.
:param nplc: Number of power line cycles (NPLC) from 0.01 to 10
:param current: Upper limit of current in Amps, from -1.05 A to 1.05 A
:param auto_range: Enables auto_range if True, else uses the set current
"""
log.info("%s is measuring current.", self.name)
self.write(":SENS:FUNC 'CURR';"
":SENS:CURR:NPLC %f;" % nplc)
if auto_range:
self.write(":SENS:CURR:RANG:AUTO 1;")
else:
self.current_range = current
self.check_errors()
def auto_range_source(self):
""" Configures the source to use an automatic range.
"""
if self.source_mode == 'current':
self.write(":SOUR:CURR:RANG:AUTO 1")
else:
self.write(":SOUR:VOLT:RANG:AUTO 1")
def apply_current(self, current_range=None,
compliance_voltage=0.1):
""" Configures the instrument to apply a source current, and
uses an auto range unless a current range is specified.
The compliance voltage is also set.
:param compliance_voltage: A float in the correct range for a
:attr:`~.Keithley2450.compliance_voltage`
:param current_range: A :attr:`~.Keithley2450.current_range` value or None
"""
log.info("%s is sourcing current.", self.name)
self.source_mode = 'current'
if current_range is None:
self.auto_range_source()
else:
self.source_current_range = current_range
self.compliance_voltage = compliance_voltage
self.check_errors()
def apply_voltage(self, voltage_range=None,
compliance_current=0.1):
""" Configures the instrument to apply a source voltage, and
uses an auto range unless a voltage range is specified.
The compliance current is also set.
:param compliance_current: A float in the correct range for a
:attr:`~.Keithley2450.compliance_current`
:param voltage_range: A :attr:`~.Keithley2450.voltage_range` value or None
"""
log.info("%s is sourcing voltage.", self.name)
self.source_mode = 'voltage'
if voltage_range is None:
self.auto_range_source()
else:
self.source_voltage_range = voltage_range
self.compliance_current = compliance_current
self.check_errors()
def beep(self, frequency, duration):
""" Sounds a system beep.
:param frequency: A frequency in Hz between 65 Hz and 2 MHz
:param duration: A time in seconds between 0 and 7.9 seconds
"""
self.write(f":SYST:BEEP {frequency:g}, {duration:g}")
def triad(self, base_frequency, duration):
""" Sounds a musical triad using the system beep.
:param base_frequency: A frequency in Hz between 65 Hz and 1.3 MHz
:param duration: A time in seconds between 0 and 7.9 seconds
"""
self.beep(base_frequency, duration)
time.sleep(duration)
self.beep(base_frequency * 5.0 / 4.0, duration)
time.sleep(duration)
self.beep(base_frequency * 6.0 / 4.0, duration)
@property
def error(self):
warn("Deprecated to use `error`, use `next_error` instead.", FutureWarning)
return self.next_error
def reset(self):
""" Resets the instrument and clears the queue. """
self.write("*RST;:stat:pres;:*CLS;")
def ramp_to_current(self, target_current, steps=30, pause=20e-3):
""" Ramps to a target current from the set current value over
a certain number of linear steps, each separated by a pause duration.
:param target_current: A current in Amps
:param steps: An integer number of steps
:param pause: A pause duration in seconds to wait between steps
"""
currents = np.linspace(
self.source_current,
target_current,
steps
)
for current in currents:
self.source_current = current
time.sleep(pause)
def ramp_to_voltage(self, target_voltage, steps=30, pause=20e-3):
""" Ramps to a target voltage from the set voltage value over
a certain number of linear steps, each separated by a pause duration.
:param target_voltage: A voltage in Amps
:param steps: An integer number of steps
:param pause: A pause duration in seconds to wait between steps
"""
voltages = np.linspace(
self.source_voltage,
target_voltage,
steps
)
for voltage in voltages:
self.source_voltage = voltage
time.sleep(pause)
def trigger(self):
""" Executes a bus trigger.
"""
return self.write("*TRG")
@property
def mean_voltage(self):
""" Returns the mean voltage from the buffer """
return self.means[0]
@property
def max_voltage(self):
""" Returns the maximum voltage from the buffer """
return self.maximums[0]
@property
def min_voltage(self):
""" Returns the minimum voltage from the buffer """
return self.minimums[0]
@property
def std_voltage(self):
""" Returns the voltage standard deviation from the buffer """
return self.standard_devs[0]
@property
def mean_current(self):
""" Returns the mean current from the buffer """
return self.means[1]
@property
def max_current(self):
""" Returns the maximum current from the buffer """
return self.maximums[1]
@property
def min_current(self):
""" Returns the minimum current from the buffer """
return self.minimums[1]
@property
def std_current(self):
""" Returns the current standard deviation from the buffer """
return self.standard_devs[1]
@property
def mean_resistance(self):
""" Returns the mean resistance from the buffer """
return self.means[2]
@property
def max_resistance(self):
""" Returns the maximum resistance from the buffer """
return self.maximums[2]
@property
def min_resistance(self):
""" Returns the minimum resistance from the buffer """
return self.minimums[2]
@property
def std_resistance(self):
""" Returns the resistance standard deviation from the buffer """
return self.standard_devs[2]
def use_rear_terminals(self):
""" Enables the rear terminals for measurement, and
disables the front terminals. """
self.write(":ROUT:TERM REAR")
def use_front_terminals(self):
""" Enables the front terminals for measurement, and
disables the rear terminals. """
self.write(":ROUT:TERM FRON")
def shutdown(self):
""" Ensures that the current or voltage is turned to zero
and disables the output. """
log.info("Shutting down %s.", self.name)
if self.source_mode == 'current':
self.ramp_to_current(0.0)
else:
self.ramp_to_voltage(0.0)
self.stop_buffer()
self.disable_source()
super().shutdown()
|