Model 335 Cryogenic Temperature Controller

The Model 335 measures and controls cryogenic temperature environments.

More information about the instrument can be found on our website including the manual which has a list of all commands and queries.

Example Scripts

Setting a temperature curve

import matplotlib.pyplot as plt
from lakeshore import Model224
from lakeshore.model_224 import Model224CurveHeader, Model224CurveFormat, Model224CurveTemperatureCoefficients, \
    Model224SoftCalSensorTypes

# Connect to a temperature instrument (the Model 224 in this case) over USB
myinstrument = Model224()

# Configure a curve by first setting its header parameters. First, set the name and serial number of the curve.
# Then, select the units used to set map the sensor units to temperature units. Set a temperature limit, and
# then specify whether the coefficients are positive or negative.
curve_header_25 = Model224CurveHeader("My_Curve", "ABC123", Model224CurveFormat.VOLTS_PER_KELVIN, 300.0,
                                      Model224CurveTemperatureCoefficients.POSITIVE)
myinstrument.set_curve_header(25, curve_header_25)

# Edit individual data points of the curve. In this case, a sensor value of 1.23 is set to equal a Kelvin value of
# 276.0
myinstrument.set_curve_data_point(25, 1, 1.23, 276.0)

# You can create a softcal curve by inputting 1-3 calibration sensor/temperature points. The instrument generates
# a new curve using your entered data points and the selected standard curve
myinstrument.generate_and_apply_soft_cal_curve(Model224SoftCalSensorTypes.DT_400, 30, "SN123", (276, 10),
                                               (300, 5), (310, 2))

# Use the get_curve method to get all the data points for a curve as a list. This can then be used to create a plot
# of the calibration curve.
data_points_list = myinstrument.get_curve(30)
x_list = [item[0] for item in data_points_list]
y_list = [item[1] for item in data_points_list]
plt.plot(x_list, y_list)

# Finally, a curve can be deleted if you would like to reset the data points for that curve. Only user curves
# can be deleted.
myinstrument.delete_curve(25)

Recording data with the Model 335

from lakeshore.model_335 import *

# Connect to the first available Model 335 temperature controller over USB using a baud rate of 57600
my_model_335 = Model335(57600)

# Create a new instance of the input sensor settings class
sensor_settings = Model335InputSensorSettings(Model335InputSensorType.DIODE, True, False,
                                              Model335InputSensorUnits.KELVIN,
                                              Model335DiodeRange.TWO_POINT_FIVE_VOLTS)

# Apply these settings to input A of the instrument
my_model_335.set_input_sensor("A", sensor_settings)

# Set diode excitation current on channel A to 10uA
my_model_335.set_diode_excitation_current("A", Model335DiodeCurrent.TEN_MICROAMPS)

# Collect instrument data
heater_output_1 = my_model_335.get_heater_output(1)
heater_output_2 = my_model_335.get_heater_output(2)
temperature_reading = my_model_335.get_all_kelvin_reading()

# Open a csv file to write
file = open("335_record_data.csv", "w")

# Write the data to the file
file.write("Data retrieved from the Lake Shore Model 335\n")
file.write("Temperature Reading A: " + str(temperature_reading[0]) + "\n")
file.write("Temperature Reading B: " + str(temperature_reading[1]) + "\n")
file.write("Heater Output 1: " + str(heater_output_1) + "\n")
file.write("Heater Output 2: " + str(heater_output_2) + "\n")
file.close()

Setting up autotune on the Model 335

from lakeshore import Model335
from lakeshore.model_335 import Model335DisplaySetup, Model335HeaterResistance, \
    Model335HeaterOutputDisplay, Model335HeaterRange, Model335AutoTuneMode, Model335HeaterError
from time import sleep

# Connect to the first available Model 335 temperature controller over USB using a baud rate of 57600
my_model_335 = Model335(57600)

# It is assumed that the instrument is configured properly with a control input sensor curve
# and heater output, capable of closed loop control

# Configure the display mode
my_model_335.set_display_setup(Model335DisplaySetup.TWO_INPUT_A)

# Configure heater output 1 using the HeaterSetup class and set_heater_setup method
my_model_335.set_heater_setup_one(Model335HeaterResistance.HEATER_50_OHM, 1.0, Model335HeaterOutputDisplay.POWER)

# Configure heater output 1 to a setpoint of 310 kelvin (units correspond to the configured output units)
set_point = 325
my_model_335.set_control_setpoint(1, set_point)

# Turn on the heater by setting the range
my_model_335.set_heater_range(1, Model335HeaterRange.HIGH)

# Check to see if there are any heater related errors
heater_error = my_model_335.get_heater_status(1)
if heater_error is not Model335HeaterError.NO_ERROR:
    raise Exception(heater_error.name)

# Allow the heater some time to turn on and start maintaining a setpoint
sleep(10)

# Ensure that the temperature is within 5 degrees kelvin of the setpoint
kelvin_reading = my_model_335.get_kelvin_reading(1)
if (kelvin_reading < (set_point - 5)) or (kelvin_reading > (set_point + 5)):
    raise Exception("Temperature reading is not within 5k of the setpoint")

# Initiate autotune in PI mode, initial conditions will not be met if the system is not
# maintaining a temperature within 5 K of the setpoint
my_model_335.set_autotune(1, Model335AutoTuneMode.P_I)

# Poll the instrument until the autotune process completes
autotune_status = my_model_335.get_tuning_control_status()
while autotune_status["active_tuning_enable"] and not autotune_status["tuning_error"]:
    autotune_status = my_model_335.get_tuning_control_status()
    # Print the status to the console every 5 seconds
    print("Active tuning: " + str(autotune_status["active_tuning_enable"]))
    print("Stage status: " + str(autotune_status["stage_status"]) + "/10")
    sleep(5)

if autotune_status["tuning_error"]:
    raise Exception("An error occurred while running autotune")

Instrument class methods

class lakeshore.model_335.Model335(baud_rate, serial_number=None, com_port=None, timeout=2.0, ip_address=None, tcp_port=None, **kwargs)

A class object representing the Lake Shore Model 335 cryogenic temperature controller

get_analog_output_percentage(output)

Returns the output percentage of the analog voltage output

Args:
output (int):
  • Specifies which analog voltage output to query
Return:
(float):
  • Analog voltage heater output percentage
set_autotune(output, mode)

Initiates autotuning of the heater control loop.

Args:
output (int):
  • Specifies the output associated with the loop to be Autotuned
mode (IntEnum):
  • Specifies the Autotune mode
  • Member of instrument’s AutoTuneMode IntEnum class
set_brightness(brightness)

Method to set the front display brightness

Args:
brightness (IntEnum)
  • A member of the instrument’s BrightnessLevel IntEnum class
get_brightness()

Method to query the front display brightness

Return:
(IntEnum):
  • A member of the instrument’s BrightnessLevel IntEnum class
get_operation_condition()

Returns the names of the operation condition register bits and their values.

get_operation_event_enable()

Returns the names of the operation event enable register and their values. These values determine which bits propagate to the operation condition register.

set_operation_event_enable(register_mask)

Configures values of the operation event enable register bits. These values determine which bits propagate to the standard event register.

Args:
register_mask (OperationEvent):
  • An OperationEvent class object with all bits configured true or false
get_operation_event()

Returns the names of the operation event register bits and their values.

get_thermocouple_junction_temp()

This method returns the temperature of the ceramic thermocouple block used in the room temperature compensation calculation

Return:
(float):
  • temperature of the ceramic thermocouple block (kelvin)
set_soft_cal_curve_dt_470(curve_number, serial_number, calibration_point_1=(4.2, 1.62622), calibration_point_2=(77.35, 1.02032), calibration_point_3=(305, 0.50691))

Creates a SoftCal curve from any 1-3 temperature/sensor points using the preconfigured DT-470 curve. When a calibration point other than one or more the default value(s) is entered a SoftCal curve is generated

Args:
curve_number (int):
  • The curve number to save the generated curve to.
  • Options are:
    • 21 - 59
serial_number (str):
  • Specifies the curve serial number.
  • Limited to 10 characters.
calibration_point_1 (tuple):
  • Tuple of two floats in the form (temperature_value, sensor_value)
  • Optional parameter
calibration_point_2 (tuple):
  • Tuple of two floats in the form (temperature_value, sensor_value)
  • Optional parameter
calibration_point_3 (tuple):
  • Tuple of two floats in the form (temperature_value, sensor_value)
  • Optional parameter
set_soft_cal_curve_pt_100(curve_number, serial_number, calibration_point_1=(77.35, 20.234), calibration_point_2=(305, 112.384), calibration_point_3=(480, 178.353))

Creates a SoftCal curve from any 1-3 temperature/sensor points using the preconfigured PT-100 curve. When a calibration point other than one or more the default value(s) is entered a SoftCal curve is generated

Args:
curve_number (int):
  • The curve number to save the generated curve to.
  • Options are:
    • 21 - 59
serial_number (str):
  • Specifies the curve serial number.
  • Limited to 10 characters.
calibration_point_1 (tuple):
  • Tuple of two floats in the form (temperature_value, sensor_value)
  • Optional parameter
calibration_point_2 (tuple):
  • Tuple of two floats in the form (temperature_value, sensor_value)
  • Optional parameter
calibration_point_3 (tuple):
  • Tuple of two floats in the form (temperature_value, sensor_value)
  • Optional parameter
set_soft_cal_curve_pt_1000(curve_number, serial_number, calibration_point_1=(77.35, 202.34), calibration_point_2=(305, 1123.84), calibration_point_3=(480, 1783.53))

Creates a SoftCal curve from any 1-3 temperature/sensor points using the preconfigured PT-1000 curve. When a calibration point other than one or more the default value(s) is entered a SoftCal curve is generated

Args:
curve_number (int):
  • The curve number to save the generated curve to.
  • Options are:
    • 21 - 59
serial_number (str):
  • Specifies the curve serial number.
  • Limited to 10 characters.
calibration_point_1 (tuple):
  • Tuple of two floats in the form (temperature_value, sensor_value)
  • Optional parameter
calibration_point_2 (tuple):
  • Tuple of two floats in the form (temperature_value, sensor_value)
  • Optional parameter
calibration_point_3 (tuple):
  • Tuple of two floats in the form (temperature_value, sensor_value)
  • Optional parameter
set_diode_excitation_current(channel, excitation_current)

The 10 uA excitation current is the only calibrated excitation current, and is used in almost all applications. The Model 336 will default the 10 uA current setting any time the input sensor type is changed.

Args:
channel (str):
  • Specifies which sensor input to configure
  • “A” - “D”
excitation_current (IntEnum):
  • A member of the instrument’s DiodeCurrent IntEnum class
get_diode_excitation_current(channel)

Returns the diode excitation current setting as a string.

Args:
channel (str):
  • Specifies which input to return
  • “A” - “D”
Return:
(IntEnum):
  • A member of the instrument’s DiodeCurrent IntEnum class
  • Diode excitation current
get_tuning_control_status()

If initial conditions are not met when starting the autotune procedure, causing the autotuning process to never actually begin, then the error status will be set to 1 and the stage status will be stage 00

Return:
(dict):
  • Keys:
  • active_tuning_enable (bool):
    • False = no active tuning, True = active tuning
  • output (int):
    • Heater output of the control loop being tuned
  • tuning_error (bool):
    • False = no tuning error, True = tuning error
  • stage_status (int):
    • Specifies the current stage in the Autotune process.
    • If tuning error occurred, stage status represents stage that failed
set_filter(input_channel, filter_enable, data_points, reset_threshold)

Configures the input_channel filter parameter

Args:
input_channel (int or str):
  • Specifies which input channel to configure
filter_enable (bool):
  • Specified whether the filtering function is enabled or not
data_points (int):
  • Specifies how many points the filter function uses
  • 2 - 64
reset_threshold (int):
  • Specifies what percent of full scale reading limits the filtering function.
  • When a raw reading differs from a filtered value by more than this threshold,
    the filter averaging resets.
  • Options are:
    • 1% - 10%
get_filter(input_channel)

Returns the input_channel filter configuration

Args:
input_channel (int or str):
  • Specifies which input channel to configure
Return:
(dict)
  • Keys:
  • “filter_enable”: bool
    • Specified whether the filtering function is enabled or not
  • “data_points”: int
    • Specifies how many points the filter function uses
  • “reset_threshold”: int
    • 1% - 10%
    • Specifies what percent of full scale reading limits the filtering function. When a raw reading differs from a filtered value by more than this threshold, the filter averaging resets.
set_monitor_output_heater(channel, high_value, low_value, units=<Model335MonitorOutUnits.KELVIN: 1>, polarity=<Polarity.UNIPOLAR: 0>)

Configures output 2. Use the set_heater_output_mode command to set the output mode to Monitor Out.

Args:
channel (Model335InputSensor):
  • Specifies which sensor input to monitor
high_value (float):
  • Represents the data at which the Monitor Out reaches +100% output
  • Entered in the units designated by the <units> argument
low_value (float):
  • Represents the data at which the analog output reaches -100% output if bipolar,
  • or 0% outputif unipolar. Entered in the units designated by the <units> argument
units (Model335MonitorOutUnits):
  • Specifies the units on which to base the output voltage
polarity (Model335Polarity):
  • Specifies output voltage is unipolar or bipolar
get_monitor_output_heater()

Used to obtain all monitor out parameters for output 2.

Return:
(dict):
  • See set_monitor_output_heater method arguments
  • Keys:
    • “channel”: Model335InputSensor
    • “units”: Model335MonitorOutUnits
    • “high_value”: float
    • “low_value”: float
    • “polarity”: Model335Polarity
get_celsius_reading(channel)

Returns the temperature value in celsius of either channel.

Args:
channel (str):
  • Selects the sensor input to query
  • “A” or “B”
set_display_setup(mode)

Sets the display mode

Args:
mode (Model335DisplaySetup):
  • Specifies the front panel display mode
  • See Model335DisplaySetup IntEnum class
get_display_setup()

Returns the display mode

Return:
(Model335DisplaySetup):
  • Specifies the front panel display mode
  • See Model335DisplaySetup IntEnum class
set_heater_setup_one(heater_resistance, max_current, output_display_mode)

Method to configure heater output one.

Args:
heater_resistance (Model335HeaterResistance):
  • See Model335HeaterResistance IntEnum class
max_current (float):
  • Specifies the maximum current for the heater
output_display_mode (Model335HeaterOutputDisplay):
  • Specifies how the heater output is displayed
  • See Model335HeaterOutType IntEnum class
set_heater_setup_two(output_type, heater_resistance, max_current, display_mode)

Method to configure the heater output 2.

Args:
output_type (Model335HeaterOutType):
  • Specifies wheter the heater output is in constant current or voltage mode
  • See Model335HeaterOutType IntEnum class
heater_resistance (Model335HeaterResistance):
  • See Model335HeaterResistance IntEnum class
max_current (float):
  • Specifies the maximum current for the heater
display_mode (Model335HeaterOutType):
  • Specifies how the heater output is displayed
  • Required only if output_type is set to CURRENT
  • See Model335HeaterOutType IntEnum class
get_heater_setup(heater_output)

Returns the heater configuration status.

Args:
heater_output (int)
  • Selects which heater output to query
Return:
(dict):
  • See set_heater_setup_one/set_heater_setup_two method arguments
  • Keys:
    • “output_type”: Model335HeaterOutType
    • “heater_resistance”: Model335HeaterResistance
    • “max_current”: float
    • “output_display_mode”: Model335HeaterOutputDisplay
set_input_sensor(channel, sensor_parameters)

Sets the sensor type and associated parameters.

Args:
channel (str):
  • Specifies input to configure
  • “A” or “B”
sensor_parameters (Model335InputSensorSettings):
  • See Model335InputSensorSettings class
get_input_sensor(channel)

Returns the sensor type and associated parameters.

Args:
channel (str):
  • Specifies sensor input to configure
  • “A” or “B”
Return:
(Model335InputSensorSettings):
  • See Model335InputSensor IntEnum class
get_all_kelvin_reading()

Returns the temperature value in kelvin of all channels.

Return:
(list: float)
  • [channel_A, channel_B]
set_heater_output_mode(output, mode, channel, powerup_enable=False)

Configures the heater output mode.

Args:
output (int):
  • Specifies which output to configure (1 or 2)
mode (Model335HeaterOutputMode):
  • Member of Model335HeaterOutputMode IntEnum class
  • Specifies the control mode
channel (Model335InputSensor)
  • Specifies which input to use for control
powerup_enable (bool)
  • Specifies whether the output remains on (True)
  • or shuts off after power cycle (False)
get_heater_output_mode(output)

Returns the heater output mode for a given output and whether powerup is enabled.

Args:
output (int):
  • Specifies which output to query (1 or 2)
Return:
(dict):
  • Keys:
    • “mode”: Model335HeaterOutputMode
    • “channel”: Model335InputSensor
    • “powerup_enable”: bool
set_output_two_polarity(output_polarity)

Sets polarity of output 2 to either unipolar or bipolar, only applicable when output 2 is in voltage mode.

Args:
output_polarity (Model335Polarity)
  • Specifies whether output voltage is UNIPOLAR or BIPOLAR
get_output_2_polarity()

Returns the polarity of output 2

Return:
(Model335Polarity)
  • Specifies whether output is UNIPOLAR or BIPOLAR
set_heater_range(output, heater_range)

Sets the heater range for a particular output. The range setting has no effect if an output is in the off mode, and does not apply to an output in Monitor Out mode. An output in Monitor Out mode is always on.

Args:
output (int):
  • Specifies which output to configure (1 or 2)
heater_range (IntEnum):
  • For Outputs 1 and 2 in Current mode:
    • Model335HeaterRange IntEnum member
  • For Output 2 in Voltage mode:
    • Model335HeaterVoltageRange IntEnum member
get_heater_range(output)

Returns the heater range for a particular output.

Args:
output (int):
  • Specifies which output to configure (1 or 2)
Return:
heater_range (IntEnum):
  • For Outputs 1 and 2 in Current mode:
    • Model335HeaterRange IntEnum member
  • For Output 2 in Voltage mode:
    • Model335HeaterVoltageRange IntEnum member
all_heaters_off()

Recreates the front panel safety feature of shutting off all heaters

get_input_reading_status(channel)

Returns the state of the input status flag bits.

Args:
channel (str):
  • Specifies which channel to query
  • “A” or “B”
Return:
(InputReadingStatus):
  • Boolean representation of each bit of the input status flag register
set_warmup_supply(control, percentage)

Warmup mode applies only to Output 2 in Voltage mode. The Output Type parameter must be configured using the set_heater_setup() method, and the Output mode and Control Input parameters must be configured using the set_monitor_out_parameters() method.

Args:
control (Model335WarmupControl):
  • Specifies the type of control used
percentage (float):
  • Specifies the percentage of full scale (10 V) Monitor Out voltage to apply
get_warmup_supply()

Returns the output 2 warmup supply configuration.

Return:
(dict):
  • Keys:
    • “control”: Model335WarmupControl
    • “percentage”: float
set_control_loop_zone_table(output, zone, control_loop_zone)

Configures the output zone parameters.

Args:
output (int):
  • Specifies which heater output to configure
  • 1 or 2
zone (int):
  • Specifies which zone in the table to configure
  • 1 to 10
control_loop_zone (ControlLoopZone):
  • See ControlLoopZone class
get_control_loop_zone_table(output, zone)

Returns a list of zone control parameters for a selected output and zone.

Args:
output (int):
  • Specifies which heater output to query
  • 1 or 2
zone (int):
  • Specifies which zone in the table to query
  • 1 to 10
Return:
(Model335ControlLoopZone):
  • See Model335ControlLoopZone class
clear_interface_command()

Clears the bits in the Status Byte Register, Standard Event Status Register, and Operation Event Register, and terminates all pending operations. Clears the interface, but not the controller.

command(*commands, check_errors=True)

Send a SCPI command or multiple commands to the instrument

Args:
commands (str):
  • A serial command
Kwargs:
check_errors (bool):
  • Chooses whether to check for and raise errors after sending a command. True by default.
connect_tcp(ip_address, tcp_port, timeout)

Establishes a TCP connection with the instrument on the specified IP address

connect_usb(serial_number=None, com_port=None, baud_rate=None, data_bits=None, stop_bits=None, parity=None, timeout=None, handshaking=None, flow_control=None)

Establish a serial USB connection

delete_curve(curve)

Deletes the user curve

Args:
curve (int):
  • Specifies a user curve to delete
disconnect_tcp()

Disconnect the TCP connection

disconnect_usb()

Disconnect the USB connection

get_alarm_parameters(input_channel)

Returns the present state of all alarm parameters

Args:
input_channel (str):
  • Specifies which input to configure
Return:
alarm_settings (AlarmSettings):
  • See AlarmSettings class
get_alarm_status(channel)

Returns the high state and low state of the alarm for the specified channel

Args:
channel (str or int)
  • Specifies which input channel to read from.
Return:
(dict)
  • Keys:
  • “high_state”: bool
    • True if high state is on, False if high state is off
  • “low_state” bool
    • True if low state is on, False if low state is off
get_control_setpoint(output)

Returns the value for a given control output

Args:
output (int):
  • Specifies which output’s control loop to query (1 or 2)
Return:
value (float):
  • The value for the setpoint (in the preferred units of the control loop sensor)
get_curve(curve)

Returns a list of all the data points in a particular curve

Args:
curve (int):
  • Specifies which curve to set
Return:
data_points (list: tuple):
  • A list containing every point in the curve represented as a tuple
    • (sensor_units: float, temp_value: float, curvature_value: float (optional))
get_curve_data_point(curve, index)

Returns a standard or user curve data point

Args:
curve (int):
  • Specifies which curve to query
index (int):
  • Specifies the points index in the curve
Return:
curve_point (tuple)
  • (sensor_units: float, temp_value: float, curvature_value: float (optional))
get_curve_header(curve_number)

Returns parameters set on a particular user curve header

Args:
curve_number (int):
  • Specifies a curve to retrieve
Returns:
(CurveHeader):
  • A CurveHeader class object containing the curve information
get_display_field_settings(field)

Returns the settings of the specified display field when display is in Custom mode.

Args:
field (int)
Defines which field of the display to retrieve settings from
Return:
(dict):
  • See set_display_field_settings method
  • Keys:
  • “input_channel”: IntEnum
  • “display_units”: IntEnum
get_heater_output(output)

Sample heater output in percent, scale is dependent upon the instrument used and heater configuration

Args:
output (int):
  • Heater output to query
Return:
(float):
  • percent of full scale current/voltage/power
get_heater_pid(output)

Returns the closed loop control parameters of the heater output

Args:
output (int):
  • Specifies which output’s control loop to query
Return:
(dict):
  • Keys:
  • “gain”: float
    • Proportional term in PID control.
  • “integral”: float
    • Integral term in PID control.
  • “ramp_rate”: float
    • Derivative term in PID control
get_heater_status(output)

Returns the heater error code state, error is cleared upon querying the heater status

Args:
output (int):
  • Specifies which heater output to query (1 or 2)
Return:
(IntEnum):
  • Object of instrument’s HeaterError type
get_ieee_488()

Returns the IEEE address set

Return:
address (int):
  • 1-30 (0 and 31 reserved)
get_input_curve(input_channel)

Returns the curve number being used for a given input

Args:
input_channel (str or int):
  • Specifies which input to query
Return:
curve_number (int):
  • 0-59
get_kelvin_reading(input_channel)

Returns the temperature value in kelvin of the given channel

Args:
input_channel:
  • Selects the channel to retrieve measurement
get_keypad_lock()

Returns the state of the keypad lock and the lock-out code.

Return:
(dict):
  • Keys:
    • “state”: bool
    • “code”: int
get_led_state()

Returns whether or not front panel LEDs are enabled.

Return:
(bool)
  • Specifies whether front panel LEDs are functional
  • False if disabled, True enabled.
get_manual_output(output)

Returns the manual output value in percent

Args:
output (int):
  • Specifies output to query
Return:
(float):
  • Manual output percent
get_min_max_data(input_channel)

Returns the minimum and maximum data from an input

Args:
input_channel (str):
  • Specifies which input to query
Return:
(dict):
  • keys:
    • “minimum”: float
    • “maximum”: float
get_relay_alarm_control_parameters(relay_number)

Returns the relay alarm configuration for either of the two configurable relays. Relay must be configured for alarm mode to retrieve parameters.

Args:
relay_number (int)
  • Specifies which relay to query
  • Options are:
    • 1 or 2
Return:
(dict):
  • Keys:
  • “activating_input_channel”: str
  • “alarm_relay_trigger_type”: RelayControlAlarm
get_relay_control_mode(relay_number)

Returns the configured mode of the specified relay.

Args:
relay_number (int):
  • Specifies which relay to query
  • Options are:
    • 1 or 2
Returns:
(IntEnum):
  • The configured mode of the relay
  • Represented as a member of the instrument’s RelayControlMode IntEnum class
get_relay_status(relay_channel)

Returns whether the relay at the specified channel is On or Off.

Args:
relay_channel (int)
  • The relay channel to query.
Returns:
(bool)
  • True if relay is on, False if relay is off.
get_remote_interface_mode()

Returns the state of the interface mode

Return:
(IntEnum):
  • A member of the instrument’s InterfaceMode IntEnum class
get_self_test()

Instrument self test result completed at power up

Return:
(bool):
  • True = errors found
  • False = no errors found
get_sensor_name(input_channel)

Returns the name of the sensor on the specified channel

Args:
input_channel (str or int):
  • Specifies which input_channel channel to read from.
Returns:
name (str)
  • Name associated with the sensor
get_sensor_reading(input_channel)

Returns the sensor reading in the sensor’s units.

Returns:
reading (float):
  • The raw sensor reading in the units of the connected sensor
get_service_request()

Returns the status byte register bits and their values as a class instance

get_setpoint_ramp_parameter(output)

Returns the control loop parameters of a particular output

Args:
output (int):
  • Specifies which output’s control loop to return
Return:
(dict):
  • Keys:
  • “ramp_enable”: bool
  • “rate_value”: float
get_setpoint_ramp_status(output)

“Returns whether or not the setpoint is ramping

Args:
output (int):
  • Specifies which output’s control loop to query
Return:
(bool):
  • Ramp status
  • False = Not ramping, True = Ramping
get_standard_event_enable_mask()

Returns the names of the standard event enable register bits and their values. These values determine which bits propagate to the standard event register

get_status_byte()

Returns the status flag bits as a class instance without resetting the register

get_temperature_limit(input_channel)

Returns the value of the temperature limit in kelvin

Args:
input_channel (str or int):
  • Specifies which input to query
query(*queries, check_errors=True)

Send a query to the instrument and return the response

Args:
queries (str):
  • A serial query ending in a question mark
Return:
  • The instrument query response as a string.
reset_alarm_status()

Clears the high and low status of all alarms.

reset_instrument()

Sets controller parameters to power-up settings

reset_min_max_data()

Resets the minimum and maximum input data

set_alarm_parameters(input_channel, alarm_enable, alarm_settings=None)

Configures the alarm parameters for an input

Args:
input_channel (str):
  • Specifies which input to configure
alarm_enable (bool):
  • Specifies whether to turn on the alarm for the input, or turn the alarm off.
alarm_settings (AlarmSettings):
  • See AlarmSettings class. Required only if alarm_enable is set to True
set_control_setpoint(output, value)

Control settings, that is, P, I, D, and Setpoint, are assigned to outputs, which results in the settings being applied to the control loop formed by the output and its control input

Args:
output (int):
  • Specifies which output’s control loop to configure
value (float):
The value for the setpoint (in the preferred units of the control loop sensor)
set_curve(curve, data_points)

Method to define a user curve using a list of data points

Args:
curve (int):
  • Specifies which curve to set
data_points (list):
  • A list containing every point in the curve represented as a tuple
    • (sensor_units: float, temp_value: float, curvature_value: float (optional))
set_curve_data_point(curve, index, sensor_units, temperature, curvature=None)

Configures a user curve point

Args:
curve (int or str):
  • Specifies which curve to configure
index (int):
  • Specifies the points index in the curve
sensor_units (float):
  • Specifies sensor units for this point to 6 digits
temperature (float):
  • Specifies the corresponding temperature in Kelvin for this point to 6 digits
curvature (float)
  • Optional argument
  • Specify only if the point is part of a cubic spindle curve
  • The curvature value scale used to calculate spindle coefficients to 6 digits
set_curve_header(curve_number, curve_header)

Configures the user curve header

Args:
curve_number:
  • Specifies which curve to configure
curve_header (CurveHeader):
  • Instrument’s CurveHeader class object containing the desired curve information
set_display_field_settings(field, input_channel, display_units)

Configures a display field when the display is in custom mode.

Args:
field (int):
  • Defines which field of the display is being configured
input_channel (IntEnum)
  • Defines which input to display.
  • A member of the instrument’s InputChannel IntEnum class
display_units (IntEnum)
  • Defines which units to display reading in.
  • A member of the instrument’s DisplayUnits IntEnum class
set_heater_pid(output, gain, integral, derivative)

Configure the closed loop control parameters of the heater output.

Args:
output (int):
  • Specifies which output’s control loop to configure
gain (float):
  • Proportional term in PID control.
  • This controls how strongly the control output reacts to the present error.
integral (float):
  • Integral term in PID control.
  • This controls how strongly the control output reacts to the past error history
derivative (float):
  • Derivative term in PID control
  • This value controls how quickly the present field setpoint will transition to a new setpoint.
  • The ramp rate is configured in field units per second.
set_ieee_488(address)

Specifies the IEEE address

Args:
address (int):
  • 1-30 (0 and 31 reserved)
set_input_curve(input_channel, curve_number)

Specifies the curve an input uses for temperature conversion

Args:
input_channel (str or int):
  • Specifies which input to configure
curve_number (int):
  • 0 = none, 1-20 = standard curves, 21-59 = user curves
set_keypad_lock(state, code)

Locks or unlocks front panel keypad (except for alarms and disabling heaters).

Args:
state (bool)
  • Sets the keypad to locked or unlocked. Options are:
  • False for unlocked or True for locked
code (int)
  • Specifies 3 digit lock-out code. Options are:
  • 000 - 999
set_led_state(state)

Sets the front panel LEDs to on or off.

Args:
state (bool)
  • Sets the LEDs to functional or nonfunctional
  • False if disabled, True enabled.
set_manual_output(output, value)

When instrument is in closed loop PID, Zone, or Open Loop modes a manual output may be set

Args:
output (int):
  • Specifies output to configure
value (float):
  • Specifies value for manual output in percent
set_relay_alarms(relay_number, activating_input_channel, alarm_relay_trigger_type)

Sets a relay to turn on and off automatically based on the state of the alarm of the specified input channel.

Args:
relay_number (int):
  • The relay to configure.
  • Options are:
    • 1 or 2
activating_input_channel (str or int):
  • Specifies which input alarm activates the relay
alarm_relay_trigger_type (RelayControlAlarm):
  • Specifies the type of alarm that triggers the relay
set_remote_interface_mode(mode)

Places the instrument in one of three interface modes

Args:
mode (IntEnum):
  • A member of the instrument’s InterfaceMode IntEnum class
set_sensor_name(input_channel, sensor_name)

Sets a given name to a sensor on the specified channel

Args:
input_channel (str or int):
  • Specifies which input_channel channel to read from
sensor_name(str):
  • Name user wants to give to the sensor on the specified channel
set_service_request(register_mask)

Manually enable/disable the mask of the corresponding status flag bit in the status byte register

Args:
register_mask (service_request_enable):
  • A service_request_enable class object with all bits configured
set_setpoint_ramp_parameter(output, ramp_enable, rate_value)

Sets the control loop of a particular output

Args:
output (int):
  • Specifies which output’s control loop to configure
ramp_enable (bool):
  • Specifies whether ramping is off or on (False = Off or True = On)
rate_value (float):
  • 0.1 to 100
  • Specifies setpoint ramp rate in kelvin per minute.
  • The rate is always positive but will respond to ramps up or down.
  • A rate of 0 is interpreted as infinite, and will respond as if setpoint ramping were off
set_standard_event_enable_mask(register_mask)

Configures values of the standard event enable register bits. These values determine which bits propagate to the standard event register

Args:
register_mask (StandardEventRegister):
An StandardEventRegister class object with all bits set to a value
set_temperature_limit(input_channel, limit)

After a set temperature limit is exceeded, all control outputs will shut down

Args:
input_channel (str or int):
  • Specifies which input to configure
limit (float):
  • The temperature limit in kelvin for which to shut down all control outputs when exceeded.
  • A limit of zero will turn the feature off
turn_relay_off(relay_number)

Turns the specified relay off.

Args:
relay_number (int):
  • The relay to turn off.
  • Options are:
    • 1 or 2
turn_relay_on(relay_number)

Turns the specified relay on.

Args:
relay_number (int):
  • The relay to turn on.
  • Options are:
    • 1 or 2

Settings classes

class lakeshore.model_335.Model335InputSensorSettings(sensor_type, autorange_enable, compensation, units, input_range=None)

Class object used in the get/set_input_sensor methods

__init__(sensor_type, autorange_enable, compensation, units, input_range=None)

Constructor for the InputSensor class

Args:
sensor_type (Model335InputSensorType):
  • Specifies input sensor type
autorange_enable (bool):
  • Specifies autoranging
  • False = off and True = on
compensation (bool):
  • Specifies input compensation
  • False = off and True = on
units (Model335InputSensorUnits):
  • Specifies the preferred units parameter for sensor readings and for the control setpoint
input_range (IntEnum)
  • Specifies input range if autorange_enable is false
  • See IntEnum classes:
    • Model335DiodeRange
    • Model335RTDRange
    • Model335ThermocoupleRange
class lakeshore.model_335.Model335ControlLoopZoneSettings(upper_bound, proportional, integral, derivative, manual_output_value, heater_range, channel, ramp_rate)

Control loop configuration for a particular heater output and zone

__init__(upper_bound, proportional, integral, derivative, manual_output_value, heater_range, channel, ramp_rate)

Constructor

Args:
upper_bound (float):
  • Specifies the upper Setpoint boundary of this zone in kelvin
proportional (float):
  • Specifies the proportional gain for this zone
  • 0.1 to 1000
integral (float):
  • Specifies the integral gain for this zone
  • 0.1 to 1000
derivative (float):
  • Specifies the derivative gain for this zone
  • 0 to 200 %
manual_output_value (float):
  • Specifies the manual output for this zone
  • 0 to 100 %
heater_range (Model335HeaterRange):
  • Specifies the heater range for this zone
  • See Model335HeaterRange IntEnum class
channel (Model335InputSensor):
  • See Model335InputSensor IntEnum class
ramp_rate (float):
  • Specifies the ramp rate for this zone
  • 0 - 100 K/min

Enumeration objects

This section describes the Enum type objects that have been created to name various settings of the Model 335 series that are represented as an int or single character to the instrument. The purpose of these enum types is to make the settings more descriptive and obvious to the user rather than interpreting the ints taken by the instrument.

lakeshore.model_335.Model335RelayControlMode

alias of lakeshore.temperature_controllers.RelayControlMode

class lakeshore.temperature_controllers.RelayControlMode

Relay operating mode enumeration

ALARMS = 2
RELAY_OFF = 0
RELAY_ON = 1
lakeshore.model_335.Model335RelayControlAlarm

alias of lakeshore.temperature_controllers.RelayControlAlarm

class lakeshore.temperature_controllers.RelayControlAlarm

Enumeration of the setting determining which alarm(s) cause a relay to close in alarm mode.

BOTH_ALARMS = 2
HIGH_ALARM = 1
LOW_ALARM = 0
lakeshore.model_335.Model335InterfaceMode

alias of lakeshore.temperature_controllers.InterfaceMode

class lakeshore.temperature_controllers.InterfaceMode

Enumeration for the mode of the remote interface

LOCAL = 0
REMOTE = 1
REMOTE_LOCAL_LOCK = 2
lakeshore.model_335.Model335HeaterError

alias of lakeshore.temperature_controllers.HeaterError

class lakeshore.temperature_controllers.HeaterError

Enumeration for possible errors flagged by the heater

HEATER_OPEN_LOAD = 1
HEATER_SHORT = 2
NO_ERROR = 0
lakeshore.model_335.Model335CurveFormat

alias of lakeshore.temperature_controllers.CurveFormat

class lakeshore.temperature_controllers.CurveFormat

Enumerations specify formats for temperature sensor curves

LOG_OHMS_PER_KELVIN = 4
MILLIVOLT_PER_KELVIN = 1
OHMS_PER_KELVIN = 3
VOLTS_PER_KELVIN = 2
lakeshore.model_335.Model335CurveTemperatureCoefficient

alias of lakeshore.temperature_controllers.CurveTemperatureCoefficient

class lakeshore.temperature_controllers.CurveTemperatureCoefficient

Enumerations specify positive/negative temperature sensor curve coefficients

NEGATIVE = 1
POSITIVE = 2
lakeshore.model_335.Model335AutoTuneMode

alias of lakeshore.temperature_controllers.AutotuneMode

class lakeshore.temperature_controllers.AutotuneMode

Enumerator used to represent the different autotune control modes

P_I = 1
P_I_D = 2
P_ONLY = 0
lakeshore.model_335.Model335HeaterResistance

alias of lakeshore.temperature_controllers.HeaterResistance

class lakeshore.temperature_controllers.HeaterResistance

Enumerator used to represent the different heater resistances

HEATER_25_OHM = 1
HEATER_50_OHM = 2
lakeshore.model_335.Model335HeaterOutputUnits

alias of lakeshore.temperature_controllers.HeaterOutputUnits

class lakeshore.temperature_controllers.HeaterOutputUnits

Enumerator used to represent heater output unit settings

CURRENT = 1
POWER = 2
class lakeshore.model_335.Model335InputSensor

Enumeration when “NONE” is an option for sensor input

CHANNEL_A = 1
CHANNEL_B = 2
NONE = 0
class lakeshore.model_335.Model335MonitorOutUnits

Units associated with a sensor channel

CELSIUS = 2
KELVIN = 1
SENSOR = 3
lakeshore.model_335.Model335Polarity

alias of lakeshore.temperature_controllers.Polarity

class lakeshore.temperature_controllers.Polarity

Enumerator for unipolar or bipolar output operation

BIPOLAR = 1
UNIPOLAR = 0
class lakeshore.model_335.Model335InputSensorType

Sensor type enumeration

DIODE = 1
DISABLED = 0
NTC_RTD = 3
PLATINUM_RTD = 2
THERMOCOUPLE = 4
lakeshore.model_335.Model335InputSensorUnits

alias of lakeshore.temperature_controllers.InputSensorUnits

class lakeshore.temperature_controllers.InputSensorUnits

Enumerator used to represent temperature sensor unit options

CELSIUS = 2
KELVIN = 1
SENSOR = 3
class lakeshore.model_335.Model335DiodeRange

Diode voltage range enumeration

TEN_VOLTS = 1
TWO_POINT_FIVE_VOLTS = 0
class lakeshore.model_335.Model335RTDRange

RTD resistance range enumeration

HUNDRED_OHM = 2
ONE_HUNDRED_THOUSAND_OHM = 8
ONE_THOUSAND_OHM = 4
TEN_OHM = 0
TEN_THOUSAND_OHM = 6
THIRTY_OHM = 1
THIRTY_THOUSAND_OHM = 7
THREE_HUNDRED_OHM = 3
THREE_THOUSAND_OHM = 5
class lakeshore.model_335.Model335ThermocoupleRange

Thermocouple range enumeration

FIFTY_MILLIVOLT = 0
lakeshore.model_335.Model335BrightnessLevel

alias of lakeshore.temperature_controllers.BrightnessLevel

class lakeshore.temperature_controllers.BrightnessLevel

Enumerator to specify the brightness level of an instrument display

FULL = 3
HALF = 1
QUARTER = 0
THREE_QUARTERS = 2
class lakeshore.model_335.Model335HeaterOutType

Heater output 2 enumeration

CURRENT = 0
VOLTAGE = 1
class lakeshore.model_335.Model335HeaterOutputDisplay

Heater output display units enumeration

CURRENT = 1
POWER = 2
class lakeshore.model_335.Model335HeaterOutputMode

Control loop enumeration

CLOSED_LOOP = 1
MONITOR_OUT = 4
OFF = 0
OPEN_LOOP = 3
WARMUP_SUPPLY = 5
ZONE = 2
class lakeshore.model_335.Model335WarmupControl

Heater output 2 voltage mode warmup enumerations

AUTO_OFF = 0
CONTINUOUS = 1
class lakeshore.model_335.Model335HeaterRange

Control loop heater range enumeration

HIGH = 3
LOW = 1
MEDIUM = 2
OFF = 0
lakeshore.model_335.Model335ControlTypes

alias of lakeshore.temperature_controllers.ControlTypes

class lakeshore.temperature_controllers.ControlTypes

Enumerator used to represent the control type settings

AUTO_OFF = 0
CONTINUOUS = 1
lakeshore.model_335.Model335DiodeCurrent

alias of lakeshore.temperature_controllers.DiodeCurrent

class lakeshore.temperature_controllers.DiodeCurrent

Enumerator used to represent diode current ranges

ONE_MILLIAMP = 1
TEN_MICROAMPS = 0
class lakeshore.model_335.Model335DisplaySetup

Panel display setup enumeration

CUSTOM = 6
INPUT_A = 0
INPUT_A_MAX_MIN = 1
INPUT_B = 3
INPUT_B_MAX_MIN = 4
TWO_INPUT_A = 2
TWO_INPUT_B = 5
TWO_LOOP = 7
class lakeshore.model_335.Model335HeaterVoltageRange

Voltage mode heater enumerations

VOLTAGE_OFF = 0
VOLTAGE_ON = 1
class lakeshore.model_335.Model335DisplayInputChannel

Panel display information enumeration

INPUT_A = 1
INPUT_B = 2
NONE = 0
OUTPUT_1 = 5
OUTPUT_2 = 6
SETPOINT_1 = 3
SETPOINT_2 = 4
class lakeshore.model_335.Model335DisplayFieldUnits

Panel display units enumeration

CELSIUS = 2
KELVIN = 1
MAXIMUM_DATA = 5
MINIMUM_DATA = 4
SENSOR_NAME = 6
SENSOR_UNITS = 3

Status register classes

This section describes the register objects. Each bit in the register is represented as a member of the register’s class

class lakeshore.model_335.Model335StatusByteRegister(message_available_summary_bit, event_status_summary_bit, service_request, operation_summary_bit)

Class object representing the status byte register LSB to MSB

class lakeshore.model_335.Model335ServiceRequestEnable(message_available_summary_bit, event_status_summary_bit, operation_summary_bit)

Class object representing the service request enable register LSB to MSB

lakeshore.model_335.Model335StandardEventRegister

alias of lakeshore.temperature_controllers.StandardEventRegister

class lakeshore.temperature_controllers.StandardEventRegister(operation_complete, query_error, execution_error, command_error, power_on)

Class object representing the standard event register

lakeshore.model_335.Model335OperationEvent

alias of lakeshore.temperature_controllers.OperationEvent

class lakeshore.temperature_controllers.OperationEvent(alarm, sensor_overload, loop_2_ramp_done, loop_1_ramp_done, new_sensor_reading, autotune_process_completed, calibration_error, processor_communication_error)

Class object representing the status byte register LSB to MSB

class lakeshore.model_335.Model335InputReadingStatus(invalid_reading, temp_underrange, temp_overrange, sensor_units_zero, sensor_units_overrange)

Class object representing the input status flag bits