semi_cr.core.lab.drivers.keithley package

Drivers for Keithley source-measure units.

class semi_cr.core.lab.drivers.keithley.Keithley2636b(*, resource_manager: Any | None = None, timeout_ms: int = 10000)

Bases: object

Control both SMU channels on a Keithley 2636B over VISA/TSP.

Source and measurement methods configure the selected channel but do not silently change its output state, except set_output and source_off.

Create a driver and its VISA resource manager.

Parameters:

• resource_manager – Optional PyVISA-compatible manager, useful when the caller shares a manager or supplies a test double.

• timeout_ms – Read/write timeout in milliseconds for the VISA session.

Raises:

ValueError – If timeout_ms is not a positive integer.

DEFAULT_TIMEOUT_MS = 10000

CHANNELS = frozenset({'a', 'b'})

FILTER_TYPES = frozenset({'FILTER_MEDIAN', 'FILTER_MOVING_AVG', 'FILTER_REPEAT_AVG'})

MIN_NPLC = 0.001

MAX_NPLC = 25.0

MIN_FILTER_COUNT = 1

MAX_FILTER_COUNT = 100

property connected: bool

Return whether a live VISA session is open.

connect(address: str) → bool

Open a VISA resource and verify that it identifies as a 2636B.

Parameters:

address – VISA resource name, for example TCPIP0::192.168.0.2::INSTR.

Returns:

True after the instrument identity has been verified.

Raises:

KeithleyConnectionError – If the resource cannot be opened, queried, or does not identify as a Keithley 2636B.

disconnect() → bool

Close the current VISA session and any resource manager owned here.

Returns:

True when the session and owned resource manager are closed.

Raises:

KeithleyDisconnectionError – If a session or owned manager fails to close.

check_connection() → bool

Query *IDN? and return whether this session reaches a 2636B.

Raises:

KeithleyConnectionError – If there is no open session or the query fails.

get_IDN() → str

Return the instrument’s raw *IDN? response.

set_source(channel: str, source: str, level: float, compliance: float | None = None) → None

Set voltage or current source mode, level, and optional compliance.

The channel output is not enabled by this method. When compliance is omitted, the instrument’s existing limit for the selected source mode is read and written back unchanged.

Parameters:

• channel – SMU channel, “a” or “b” (case-insensitive).

• source – Source mode, “voltage” or “current”.

• level – Source level in volts or amperes, according to source.

• compliance – Optional positive current limit in voltage mode or voltage limit in current mode.

Raises:

• ValueError – If a channel, mode, level, or compliance value is invalid.

• KeithleyConnectionError – If the VISA session or TSP command fails.

set_compliance(channel: str, compliance: float) → None

Set the active mode’s current or voltage compliance limit.

Parameters:

• channel – SMU channel, “a” or “b” (case-insensitive).

• compliance – Positive limit in amperes for voltage mode or volts for current mode.

Raises:

• ValueError – If the channel or limit is invalid.

• KeithleyConnectionError – If the session or TSP command fails.

set_filter(channel: str, filter_type: str) → None

Set the digital measurement filter algorithm for one channel.

Parameters:

• channel – SMU channel, “a” or “b” (case-insensitive).

• filter_type – One of FILTER_REPEAT_AVG, FILTER_MOVING_AVG, or FILTER_MEDIAN.

Raises:

• ValueError – If the channel or filter type is unsupported.

• KeithleyConnectionError – If the session or TSP command fails.

set_nplc(channel: str, nplc: float) → None

Set the measurement integration time in power-line cycles.

Parameters:

• channel – SMU channel, “a” or “b” (case-insensitive).

• nplc – Integration time from 0.001 through 25 power-line cycles.

Raises:

• ValueError – If the channel or NPLC is outside the supported range.

• KeithleyConnectionError – If the session or TSP command fails.

set_settling_time(channel: str, time: float) → None

Set the source delay in seconds; use -1 for automatic delay.

Parameters:

• channel – SMU channel, “a” or “b” (case-insensitive).

• time – Non-negative delay in seconds, or -1 for range-dependent delay.

Raises:

• ValueError – If the channel or delay is invalid.

• KeithleyConnectionError – If the session or TSP command fails.

get_source(channel: str) → dict[str, str | float]

Read source mode and active source level from one channel.

Parameters:

channel – SMU channel, “a” or “b” (case-insensitive).

Returns:

A dictionary with source (“voltage” or “current”) and level.

Raises:

• KeithleyMeasurementError – If the source mode cannot be decoded.

• KeithleyConnectionError – If a query fails.

get_compliance(channel: str) → float

Read the compliance limit for the channel’s active source mode.

Parameters:

channel – SMU channel, “a” or “b” (case-insensitive).

Returns:

Current limit in amperes for voltage mode, or voltage limit in volts for current mode.

get_filter(channel: str) → str

Read the configured digital measurement filter type.

Parameters:

channel – SMU channel, “a” or “b” (case-insensitive).

Returns:

The filter constant name.

Raises:

KeithleyMeasurementError – If the instrument returns an unknown filter.

get_nplc(channel: str) → float

Read the measurement integration time in power-line cycles.

Parameters:

channel – SMU channel, “a” or “b” (case-insensitive).

Returns:

The configured NPLC value.

get_settling_time(channel: str) → float

Read source delay in seconds, returning -1 for automatic delay.

Parameters:

channel – SMU channel, “a” or “b” (case-insensitive).

Returns:

The configured delay in seconds or -1.0 when delay is automatic.

measure_resistance(channel: str) → float

Take and return one resistance reading without changing output state.

measure_voltage(channel: str) → float

Take and return one voltage reading without changing output state.

measure_current(channel: str) → float

Take and return one current reading without changing output state.

measure_power(channel: str) → float

Take and return one power reading without changing output state.

set_output(channel: str, enabled: bool) → bool

Set and verify whether one channel’s source output is enabled.

Parameters:

• channel – SMU channel, “a” or “b” (case-insensitive).

• enabled – True to enable output, False to disable it.

Returns:

The output state read back from the instrument.

get_output_enabled(channel: str) → bool

Read and decode the source output state for one channel.

Parameters:

channel – SMU channel, “a” or “b” (case-insensitive).

Returns:

Whether the channel output is enabled.

Raises:

KeithleyMeasurementError – If the instrument returns an unknown state.

source_off() → None

Disable and verify both SMU outputs.

set_measure(channel: str, *, nplc: float, filter_enabled: bool, filter_type: str, filter_count: int, voltage_range: float | None = None, current_range: float | None = None) → None

Configure integration time, digital filtering, and autorange/ranges.

Parameters:

• channel – SMU channel, “a” or “b” (case-insensitive).

• nplc – Measurement integration time, from 0.001 to 25 PLC.

• filter_enabled – Whether to enable the selected digital filter.

• filter_type – Supported Keithley filter constant.

• filter_count – Filter count from 1 to 100.

• voltage_range – Fixed voltage measurement range; None enables autorange.

• current_range – Fixed current measurement range; None enables autorange.

Raises:

• ValueError – If any supplied setting is outside the supported range.

• KeithleyConnectionError – If a TSP command fails.

exception semi_cr.core.lab.drivers.keithley.KeithleyConnectionError

Bases: KeithleyError

Raised when the VISA session is unavailable or communication fails.

add_note()

Exception.add_note(note) – add a note to the exception

args

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception semi_cr.core.lab.drivers.keithley.KeithleyDisconnectionError

Bases: KeithleyConnectionError

Raised when the VISA resource manager or session cannot be closed.

add_note()

Exception.add_note(note) – add a note to the exception

args

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception semi_cr.core.lab.drivers.keithley.KeithleyError

Bases: RuntimeError

Base error raised by the Keithley 2636B driver.

add_note()

Exception.add_note(note) – add a note to the exception

args

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception semi_cr.core.lab.drivers.keithley.KeithleyMeasurementError

Bases: KeithleyError

Raised when a response from the instrument cannot be interpreted.

add_note()

Exception.add_note(note) – add a note to the exception

args

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

Subpackages

• semi_cr.core.lab.drivers.keithley.hardware_test package
  • Submodules
  • semi_cr.core.lab.drivers.keithley.hardware_test.test_keithley_2636b_hardware module
    • test_keithley_2636b_full_hardware_round_trip()

Submodules

semi_cr.core.lab.drivers.keithley.keithley_2636b module

PyVISA driver for the two-channel Keithley 2636B SourceMeter.

class semi_cr.core.lab.drivers.keithley.keithley_2636b.Keithley2636b(*, resource_manager: Any | None = None, timeout_ms: int = 10000)

Bases: object

Control both SMU channels on a Keithley 2636B over VISA/TSP.

Source and measurement methods configure the selected channel but do not silently change its output state, except set_output and source_off.

Create a driver and its VISA resource manager.

Parameters:

• resource_manager – Optional PyVISA-compatible manager, useful when the caller shares a manager or supplies a test double.

• timeout_ms – Read/write timeout in milliseconds for the VISA session.

Raises:

ValueError – If timeout_ms is not a positive integer.

DEFAULT_TIMEOUT_MS = 10000

CHANNELS = frozenset({'a', 'b'})

FILTER_TYPES = frozenset({'FILTER_MEDIAN', 'FILTER_MOVING_AVG', 'FILTER_REPEAT_AVG'})

MIN_NPLC = 0.001

MAX_NPLC = 25.0

MIN_FILTER_COUNT = 1

MAX_FILTER_COUNT = 100

device: Any | None

property connected: bool

Return whether a live VISA session is open.

connect(address: str) → bool

Open a VISA resource and verify that it identifies as a 2636B.

Parameters:

address – VISA resource name, for example TCPIP0::192.168.0.2::INSTR.

Returns:

True after the instrument identity has been verified.

Raises:

KeithleyConnectionError – If the resource cannot be opened, queried, or does not identify as a Keithley 2636B.

disconnect() → bool

Close the current VISA session and any resource manager owned here.

Returns:

True when the session and owned resource manager are closed.

Raises:

KeithleyDisconnectionError – If a session or owned manager fails to close.

check_connection() → bool

Query *IDN? and return whether this session reaches a 2636B.

Raises:

KeithleyConnectionError – If there is no open session or the query fails.

get_IDN() → str

Return the instrument’s raw *IDN? response.

set_source(channel: str, source: str, level: float, compliance: float | None = None) → None

Set voltage or current source mode, level, and optional compliance.

The channel output is not enabled by this method. When compliance is omitted, the instrument’s existing limit for the selected source mode is read and written back unchanged.

Parameters:

• channel – SMU channel, “a” or “b” (case-insensitive).

• source – Source mode, “voltage” or “current”.

• level – Source level in volts or amperes, according to source.

• compliance – Optional positive current limit in voltage mode or voltage limit in current mode.

Raises:

• ValueError – If a channel, mode, level, or compliance value is invalid.

• KeithleyConnectionError – If the VISA session or TSP command fails.

set_compliance(channel: str, compliance: float) → None

Set the active mode’s current or voltage compliance limit.

Parameters:

• channel – SMU channel, “a” or “b” (case-insensitive).

• compliance – Positive limit in amperes for voltage mode or volts for current mode.

Raises:

• ValueError – If the channel or limit is invalid.

• KeithleyConnectionError – If the session or TSP command fails.

set_filter(channel: str, filter_type: str) → None

Set the digital measurement filter algorithm for one channel.

Parameters:

• channel – SMU channel, “a” or “b” (case-insensitive).

• filter_type – One of FILTER_REPEAT_AVG, FILTER_MOVING_AVG, or FILTER_MEDIAN.

Raises:

• ValueError – If the channel or filter type is unsupported.

• KeithleyConnectionError – If the session or TSP command fails.

set_nplc(channel: str, nplc: float) → None

Set the measurement integration time in power-line cycles.

Parameters:

• channel – SMU channel, “a” or “b” (case-insensitive).

• nplc – Integration time from 0.001 through 25 power-line cycles.

Raises:

• ValueError – If the channel or NPLC is outside the supported range.

• KeithleyConnectionError – If the session or TSP command fails.

set_settling_time(channel: str, time: float) → None

Set the source delay in seconds; use -1 for automatic delay.

Parameters:

• channel – SMU channel, “a” or “b” (case-insensitive).

• time – Non-negative delay in seconds, or -1 for range-dependent delay.

Raises:

• ValueError – If the channel or delay is invalid.

• KeithleyConnectionError – If the session or TSP command fails.

get_source(channel: str) → dict[str, str | float]

Read source mode and active source level from one channel.

Parameters:

channel – SMU channel, “a” or “b” (case-insensitive).

Returns:

A dictionary with source (“voltage” or “current”) and level.

Raises:

• KeithleyMeasurementError – If the source mode cannot be decoded.

• KeithleyConnectionError – If a query fails.

get_compliance(channel: str) → float

Read the compliance limit for the channel’s active source mode.

Parameters:

channel – SMU channel, “a” or “b” (case-insensitive).

Returns:

Current limit in amperes for voltage mode, or voltage limit in volts for current mode.

get_filter(channel: str) → str

Read the configured digital measurement filter type.

Parameters:

channel – SMU channel, “a” or “b” (case-insensitive).

Returns:

The filter constant name.

Raises:

KeithleyMeasurementError – If the instrument returns an unknown filter.

get_nplc(channel: str) → float

Read the measurement integration time in power-line cycles.

Parameters:

channel – SMU channel, “a” or “b” (case-insensitive).

Returns:

The configured NPLC value.

get_settling_time(channel: str) → float

Read source delay in seconds, returning -1 for automatic delay.

Parameters:

channel – SMU channel, “a” or “b” (case-insensitive).

Returns:

The configured delay in seconds or -1.0 when delay is automatic.

measure_resistance(channel: str) → float

Take and return one resistance reading without changing output state.

measure_voltage(channel: str) → float

Take and return one voltage reading without changing output state.

measure_current(channel: str) → float

Take and return one current reading without changing output state.

measure_power(channel: str) → float

Take and return one power reading without changing output state.

set_output(channel: str, enabled: bool) → bool

Set and verify whether one channel’s source output is enabled.

Parameters:

• channel – SMU channel, “a” or “b” (case-insensitive).

• enabled – True to enable output, False to disable it.

Returns:

The output state read back from the instrument.

get_output_enabled(channel: str) → bool

Read and decode the source output state for one channel.

Parameters:

channel – SMU channel, “a” or “b” (case-insensitive).

Returns:

Whether the channel output is enabled.

Raises:

KeithleyMeasurementError – If the instrument returns an unknown state.

source_off() → None

Disable and verify both SMU outputs.

set_measure(channel: str, *, nplc: float, filter_enabled: bool, filter_type: str, filter_count: int, voltage_range: float | None = None, current_range: float | None = None) → None

Configure integration time, digital filtering, and autorange/ranges.

Parameters:

• channel – SMU channel, “a” or “b” (case-insensitive).

• nplc – Measurement integration time, from 0.001 to 25 PLC.

• filter_enabled – Whether to enable the selected digital filter.

• filter_type – Supported Keithley filter constant.

• filter_count – Filter count from 1 to 100.

• voltage_range – Fixed voltage measurement range; None enables autorange.

• current_range – Fixed current measurement range; None enables autorange.

Raises:

• ValueError – If any supplied setting is outside the supported range.

• KeithleyConnectionError – If a TSP command fails.

exception semi_cr.core.lab.drivers.keithley.keithley_2636b.KeithleyConnectionError

Bases: KeithleyError

Raised when the VISA session is unavailable or communication fails.

add_note()

Exception.add_note(note) – add a note to the exception

args

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception semi_cr.core.lab.drivers.keithley.keithley_2636b.KeithleyDisconnectionError

Bases: KeithleyConnectionError

Raised when the VISA resource manager or session cannot be closed.

add_note()

Exception.add_note(note) – add a note to the exception

args

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception semi_cr.core.lab.drivers.keithley.keithley_2636b.KeithleyError

Bases: RuntimeError

Base error raised by the Keithley 2636B driver.

add_note()

Exception.add_note(note) – add a note to the exception

args

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception semi_cr.core.lab.drivers.keithley.keithley_2636b.KeithleyMeasurementError

Bases: KeithleyError

Raised when a response from the instrument cannot be interpreted.

add_note()

Exception.add_note(note) – add a note to the exception

args

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.