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, Model224CurveHeader

# 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", myinstrument.CurveFormat.VOLTS_PER_KELVIN, 300.0,
                                      myinstrument.CurveTemperatureCoefficients.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(myinstrument.SoftCalSensorTypes.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 import Model335, Model335InputSensorSettings

# 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(my_model_335.InputSensorType.DIODE, True, False,
                                              my_model_335.InputSensorUnits.KELVIN,
                                              my_model_335.DiodeRange.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", my_model_335.DiodeCurrent.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 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(my_model_335.DisplaySetup.TWO_INPUT_A)

# Configure heater output 1 using the HeaterSetup class and set_heater_setup method
my_model_335.set_heater_setup_one(my_model_335.HeaterResistance.HEATER_50_OHM, 1.0, my_model_335.HeaterOutputDisplay.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, my_model_335.HeaterRange.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 my_model_335.HeaterError.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, my_model_335.AutotuneMode.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.

Returns:

(float):

Analog voltage heater output percentage.

set_autotune(output, mode)

Initiates auto-tuning of the heater control loop.

Args:

output (int):

Specifies the output associated with the loop to be Auto-tuned.

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.

Returns:

(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()

Returns the temperature of the ceramic thermocouple block from the room temperature compensation calculation.

Returns:

(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)

Sets the excitation current of a specific channel.

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”.

Returns:

(IntEnum):

A member of the instrument’s DiodeCurrent IntEnum class. Diode excitation current.

get_tuning_control_status()

Returns dictionary of tuning control status values.

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

Returns:

(dict):

{“active_tuning_enable”: bool, “output”: int, “tuning_error”: bool, “stage_status”: int}

active_tuning_enable: False = no active tuning, True = active tuning. output: Heater output of the control loop being tuned. tuning_error: False = no tuning error, True = tuning error. stage_status: 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.

Returns:

(dict)

{“filter_enable”: bool, “data_points”: int, “reset_threshold”: int}

filter_enable: Specified whether the filtering function is enabled or not. data_points: Specifies how many points the filter function uses. reset_threshold: 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 (1% - 10%).

set_monitor_output_heater(channel, high_value, low_value, units=MonitorOutUnits.KELVIN, polarity=Polarity.UNIPOLAR)

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% output if 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.

Returns:

(dict):

{“channel”: Model335InputSensor, “units”: Model335MonitorOutUnits, “high_value”: float, “low_value”: float, “polarity”: Model335Polarity}

See set_monitor_output_heater method arguments

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 whether 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. {“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): {“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):

{“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.

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, True = on).

compensation (bool):

Specifies input compensation. (False = off, True = on).

units (Model335InputSensorUnits):

Specifies the preferred units parameter for sensor readings and for the control set-point.

input_range (IntEnum)

Specifies input range if autorange_enable is false. See IntEnum classes: Model335DiodeRange, Model335RTDRange, and 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 set-point 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.

class lakeshore.model_335.Model335Enums

Class containing the enums relevant to the Model 335.

class InputSensor(value)

Enumeration when “NONE” is an option for sensor input.

NONE = 0

CHANNEL_A = 1

CHANNEL_B = 2

class MonitorOutUnits(value)

Units associated with a sensor channel.

KELVIN = 1

CELSIUS = 2

SENSOR = 3

class InputSensorType(value)

Sensor type enumeration.

DISABLED = 0

DIODE = 1

PLATINUM_RTD = 2

NTC_RTD = 3

THERMOCOUPLE = 4

class DiodeRange(value)

Diode voltage range enumeration.

TWO_POINT_FIVE_VOLTS = 0

TEN_VOLTS = 1

class RTDRange(value)

RTD resistance range enumeration.

TEN_OHM = 0

THIRTY_OHM = 1

HUNDRED_OHM = 2

THREE_HUNDRED_OHM = 3

ONE_THOUSAND_OHM = 4

THREE_THOUSAND_OHM = 5

TEN_THOUSAND_OHM = 6

THIRTY_THOUSAND_OHM = 7

ONE_HUNDRED_THOUSAND_OHM = 8

class ThermocoupleRange(value)

Thermocouple range enumeration.

FIFTY_MILLIVOLT = 0

class HeaterOutType(value)

Heater output 2 enumeration.

CURRENT = 0

VOLTAGE = 1

class HeaterOutputDisplay(value)

Heater output display units enumeration.

CURRENT = 1

POWER = 2

class HeaterOutputMode(value)

Control loop enumeration.

OFF = 0

CLOSED_LOOP = 1

ZONE = 2

OPEN_LOOP = 3

MONITOR_OUT = 4

WARMUP_SUPPLY = 5

class WarmupControl(value)

Heater output 2 voltage mode warmup enumerations.

AUTO_OFF = 0

CONTINUOUS = 1

class HeaterRange(value)

Control loop heater range enumeration.

OFF = 0

LOW = 1

MEDIUM = 2

HIGH = 3

class DisplaySetup(value)

Panel display setup enumeration.

INPUT_A = 0

INPUT_A_MAX_MIN = 1

TWO_INPUT_A = 2

INPUT_B = 3

INPUT_B_MAX_MIN = 4

TWO_INPUT_B = 5

CUSTOM = 6

TWO_LOOP = 7

class HeaterVoltageRange(value)

Voltage mode heater enumerations.

VOLTAGE_OFF = 0

VOLTAGE_ON = 1

class InputChannel(value)

Panel display information enumeration.

NONE = 0

INPUT_A = 1

INPUT_B = 2

SETPOINT_1 = 3

SETPOINT_2 = 4

OUTPUT_1 = 5

OUTPUT_2 = 6

class DisplayFieldUnits(value)

Panel display units enumeration.

KELVIN = 1

CELSIUS = 2

SENSOR_UNITS = 3

MINIMUM_DATA = 4

MAXIMUM_DATA = 5

SENSOR_NAME = 6

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 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 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.