Model 240 Input Modules

The 240 Series Input Modules employ distributed PLC control for large scale cryogenic temperature monitoring.

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

Model 240 Input Channel Setup Example

from lakeshore import Model240
from lakeshore.model_240 import Model240InputParameter, Model240SensorTypes, Model240Units, Model240InputRange
from time import sleep

# Connect to the first available Model 240 over USB
my_model_240 = Model240()

# Define the channel configuration for a sensor with a negative temperature coefficient, autorange disabled
# current reversal disabled, the channel enabled, and set to the 100 kOhm range
rtd_config = Model240InputParameter(Model240SensorTypes.NTC_RTD, False, False, Model240Units.SENSOR, True,
                                    Model240InputRange.RANGE_NTCRTD_100_KIL_OHMS)

# Apply the configuration to all channels
for channel in range(1, 9):
    my_model_240.set_input_parameter(channel, rtd_config)

sleep(1)
print("Reading from channel 5: {} ohms".format(my_model_240.get_sensor_reading(5)))

Model 240 Profibus Configuration Example

from lakeshore import Model240, Model240Units, Model240ProfiSlot

# Connect to the first available Model 240 over USB
my_model_240 = Model240()

# Print the instrument's current PROFIBUS connection status to the console
print("Profibus connection status: " + my_model_240.get_profibus_connection_status())

# Configure the number of PROFIBUS slots for the instrument to present to the bus as a modular station
# Setting the number of PROFIBUS slots to 2
my_model_240.set_profibus_slot_count(2)

# Create the ProfiSlot class object by specifying which input to associate the
# slot with and what temperature units the data will be presented in
# Setting the input channel as 2 and temperature units to Celsius
my_profibus_slot = Model240ProfiSlot(2, Model240Units.CELSIUS)

# Configure what data to be presented on the given PROFIBUS slot
# Profibus slot 1 will be associated with channel 2
my_model_240.set_profibus_slot_configuration(1, my_profibus_slot)

# Print the PROFIBUS address
# An address of 126 indicates that it is not configured and it can then be set by a PROFIBUS master
print("Profibus adress: " + my_model_240.get_profibus_address())

# Set the desired address as 123
my_model_240.set_profibus_address("123")

# Acquiring settings that were configured above
print(my_model_240.get_profibus_slot_count())
slot_1_config = my_model_240.get_profibus_slot_configuration(1)
print(slot_1_config.slot_channel)
print(slot_1_config.slot_units)

Instrument class methods

class lakeshore.model_240.Model240(serial_number=None, com_port=None, timeout=2.0, **kwargs)

A class object representing the Lake Shore Model 240 channel modules

get_identification()

Returns instrument’s identification parameters.

Returns:
id (list):
List defining instrument’s manufacturer, model, instrument serial, firmware version
set_brightness(brightness_level)

Sets the brightness for the front panel display

Args:
brightness_level (Model240BrightnessLevel):
  • Display brightness in percent
get_brightness()

Returns the brightness level of front panel display

Return:
brightness_level (Model240BrightnessLevel):
  • Display brightness in percent
get_celsius_reading(channel)

Returns the temperature value in Celsius of channel selected.

Args:
channel (int):
Specifies channel (1-8)
set_factory_defaults()

Sets all configuration values to factory defaults and resets the instrument

get_kelvin_reading(channel)

Returns the temperature value in Kelvin of channel selected.

Args:
channel (int):
Specifies channel (1-8)
get_fahrenheit_reading(channel)

Returns the temperature value in Farenheit of channel selected

Args:
channel (int):
Specifies channel (1-8)
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
delete_curve(curve)

Deletes the user curve

Args:
curve (int):
  • Specifies a user curve to delete
set_curve_header(input_channel, curve_header)

Configures the user curve header

Args:
input_channel (int):
  • Specifies which input_channel curve to configure
  • 1 - 8
curve_header (CurveHeader):
  • A CurveHeader class object containing the desired curve information
get_curve_header(curve)

Returns parameters set on a particular user curve header

Args:
curve:
  • Specifies a curve to retrieve
Returns:
header (CurveHeader):
  • A CurveHeader class object containing the desired curve information
set_curve_data_point(channel, index, units, temp)

Configures a user curve point

Args:
channel (int):
Specifies which channel curve to configure (1-8)
index (int):
Specifies the points index in the curve (1-200)
units (float):
Specifies sensor units for this point to 6 digits
temp (float):
Specifies the corresponding temperature in Kelvin for this point to 6 digits
get_curve_data_point(channel, index)

Returns a standard or user curve data point

Args:
channel (int):
Specifies channel (1-8)
index (int):
Specifies the points index in the curve (1–200)
set_filter(channel, length)

Sets the channel filter parameter

Args:
channel (int):
Specifies which channel to configure (1-8)
length (int):
Specifies the number of 1 ms points to average for each update (1-100)
get_filter(channel)

Returns the filter parameter

Args:
channel (int):
Specifies channel (1-8)
set_sensor_name(channel, name)

Names the sensor channel in specified channel.

Args:
channel (int):
Specifies which channel to configure (1-8)
name (str):
Specifies the name to associate with the sensor channel
get_sensor_name(channel)

Returns the sensor channel’s name.

Args:
channel (int):
Specifies channel (1-8)
set_input_parameter(channel, input_parameter)

Sets channel type parameters.

Args:
channel (int):
Specifies which channel to configure (1-8)
input_parameter (InputParameter):
See InputParameter class
get_input_parameter(channel)

Returns channel type parameter details

Args:
channel (int):
Specifies channel (1-8)
set_modname(name)

Names module.

Args:
name (str):
Specifies the name or description to help identify the module
get_modname()

Returns module name

Returns:
modname (str):
Specifies name of module
set_profibus_slot_count(count)

Configures the number of PROFIBUS slots for the instrument to present to the bus as a modular station

Args:
count (int):
Specifies the number of PROFIBUS slots (1-8)
get_profibus_slot_count()

Returns the number of PROFIBUS slots for the instrument present to the bus as a modular station

Returns:
slot_count (str):
Specifies PROFIBUS slot count
set_profibus_address(address)

Configures the PROFIBUS address for the module. An address of 126 indicates that it is not configured and it then can be set by a PROFIBUS master.

Args:
address (str):
Specifies the PROFIBUS address (1-126)
get_profibus_address()

Returns the PROFIBUS address for the module.

Returns:
address (str):
Specifies PROFIBUS address of module
set_profibus_slot_configuration(slot, profislot_config)

Configures what data to present on the given PROFIBUS slot. Note that the correct number of slots must be configured with the PROFINUM command, or the slot may be ignored.

Args:
slot (int):
Specifies the slot to be configured
profislot_config (Model240ProfiSlot):
A Model240ProfiSlot class object containing the desired PROFIBUS slot configuration information
get_profibus_slot_configuration(slot_num)

Returns the slot configuration of the slot number.

Returns:
slot_config (Model240ProfiSlot):
See Model240ProfiSlot class
get_profibus_connection_status()

Returns the connection status of PROFIBUS.

Returns:
status (str):
Specifies connection status of PROFIBUS
get_channel_reading_status(channel)

The integer returned represents the sum of the bit weighting of the channel status flag bits. A “000” response indicates a valid reading is present.

Args:
channel (int):
Specifies which channel to query (1-8)
Returns:
bit_status (dict):
Dictionary containing the current status indicator
get_sensor_units_channel_reading(channel)

Returns the sensor units value of channel being queried

Args:
channel (int):
Specifies which channel to query (1-8)
command(command_string)

Send a command to the instrument

Args:
command_string (str):
A serial command
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

disconnect_tcp()

Disconnect the TCP connection

disconnect_usb()

Disconnect the USB connection

query(query_string)

Send a query to the instrument and return the response

Args:
query_string (str):
A serial query ending in a question mark
Returns:
The instrument query response as a string.

Settings classes

This page describes the classes used throughout the 240 methods that interact with instrument settings and other methods that use objects and classes.

class lakeshore.model_240.Model240CurveHeader(curve_name, serial_number, curve_data_format, temperature_limit, coefficient)

A class that configures the user curve header and corresponding parameters

__init__(curve_name, serial_number, curve_data_format, temperature_limit, coefficient)

Constructor for CurveHeader class

Args:
curve_name (str):
  • Specifies curve name (limit of 15 characters)
serial_number (str):
  • Specifies curve serial number (limit of 10 characters)
curve_data_format (Model240CurveFormat):
  • Specifies the curve data format
temperature_limit (float):
  • Specifies the curve temperature limit in Kelvin
coefficient (Model240TemperatureCoefficient):
  • Specifies the curve temperature coefficient
class lakeshore.model_240.Model240InputParameter(sensor, auto_range_enable, current_reversal_enable, units, input_enable, input_range=None)

Class used to retrieve and set an input channel’s parameters and initial settings.

__init__(sensor, auto_range_enable, current_reversal_enable, units, input_enable, input_range=None)

The constructor for InputParameter class.

Args:

sensor (Model240SensorTypes):
  • Specifies the type of sensor configured at the input
  • Member of the Model240SensorTypes IntEnum class
auto_range_enable (bool):
Specifies if autoranging is enabled
current_reversal_enable (bool):
  • Specifies channel current reversal
  • Current reversal is used to remove thermal EMF errors on resistive sensors.
  • Always False if channel is a diode
  • False = OFF, True = ON
units (Model240Units):
  • Member of the Model240Units IntEnum class
  • Specifies the preferred units parameter.
input_enable (bool):
Specifies whether the channel is disabled or enabled
input_range (Model240InputRange):
Specifies channel range when autorange is off
class lakeshore.model_240.Model240ProfiSlot(channel, temp_unit)

Class used to configure and retrieve data for given PROFIBUS slot.

__init__(channel, temp_unit)

The constructor for Model240ProfiSlot class.

Args:
channel (int):
Specifies which slot to configure (1-8)
temp_unit (Model240Units):
  • Member of Model240Units IntEnum class
  • Specifies the units to use for the data in this slot

Enumeration objects

This section describes the Enum type objects that have been created to name various settings of the Model 240 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_240.Model240Units

Enumerations that specify temperature units

CELSIUS = 2
FAHRENHEIT = 4
KELVIN = 1
SENSOR = 3
class lakeshore.model_240.Model240CurveFormat

Enumerations that specify temperature sensor curve format units

LOG_OHMS_PER_KELVIN = 4
OHMS_PER_KELVIN = 3
VOLTS_PER_KELVIN = 2
class lakeshore.model_240.Model240Coefficients

Enumerations that specify a positive or negative coefficient

NEGATIVE = 1
POSITIVE = 2
class lakeshore.model_240.Model240SensorTypes

Enumerations specify types of temperature sensors

DIODE = 1
NTC_RTD = 3
PLATINUM_RTD = 2
class lakeshore.model_240.Model240BrightnessLevel

Enumerations for the screen brightness levels

HIGH = 100
LOW = 25
MED_HIGH = 75
MED_LOW = 50
OFF = 0
class lakeshore.model_240.Model240TemperatureCoefficient

Enumerations specify positive/negative temperature sensor curve coefficients

NEGATIVE = 1
POSITIVE = 2
class lakeshore.model_240.Model240InputRange

Enumerations to specify the input range when autorange is off

RANGE_DIODE = 0
RANGE_NTCRTD_100_KIL_OHMS = 8
RANGE_NTCRTD_100_OHMS = 2
RANGE_NTCRTD_10_KIL_OHMS = 6
RANGE_NTCRTD_10_OHMS = 0
RANGE_NTCRTD_1_KIL_OHMS = 4
RANGE_NTCRTD_30_KIL_OHMS = 7
RANGE_NTCRTD_30_OHMS = 1
RANGE_NTCRTD_3_KIL_OHMS = 5
RANGE_PTRTD_1_KIL_OHMS = 0