Linear range class functions.LinearRange does return an empty sequence if step exceeds the absolute ramp distance.

>>> list(LinearRange(0, 1, 5))
[]

It should return

>>> list(LinearRange(0, 1, 5))
[0.0, 1.0]

To verify a connection to an instrument it would be convenient to have an action to manually test the connection specified in role resource settings (resource name, termination, timeout) an returning the instrument identification to verify the instrument used.

To catch the attention of the operator it would be useful to have the stop button colored in red while a measurement is running.

It might be required to switch the application to Fusion style (native Windows style lacks decent coloring).

Configuring instrument specific options is broken in version 0.15.1 (wrong dictionary is applied).

Make write output to file optional to prevent creating unwanted output files on disk.

If running CV type measurements, add following LCR parameters to the output header:

• lcr_ac_amplitude[V]
• lcr_ac_frequency[Hz]

Add support for HEPHY Environment Box

• read temperature/humidity
• control PID, Lights, etc.

Propagate It readings using a thread-safe queue rather then Qt's signal/slot mechanism to prevent slow down of the measurement loop when measuring at high rates (eg. up to 200Hz).

Also writing to an output file should be decoupled using a dedicated thread and queue.

There is a typo in an SCPI message to the instrument :FUNC CURR should be :FUNC 'CURR' (with single quotes). This bug affects both K6514 and K6517B models.

There is a bug preventing instrument settings to be loaded/saved in version 0.13.0

To apply a bias voltage and monitor a bias current add a new role SMU2 and a new measurement type "IV Bias".

Currently the Electrometer sense ranges are limited to 0.001 uA in the user interface, however some measurements require a sense range in the pA range.

A quick fix might be to increase the decimals from 3 to six.

the two fields with "waiting time" (one for IV and the other for IT) should be restricted to a minimum of 1 second. This is related to issue #12

With Python > 3.6 installing PyInstaller 4.3 fails building a wheel from source distribution on Windows.

Migrate to PyInstaller==4.10.*

Note: for IV measurements, when selecting only ELM instrument, the ELM acts as voltage source (if the instrument supports it).

Implement following methods for K6517B drivers:

• get_output_enabled() -> bool
• set_output_enabled(enabled: bool) -> None
• get_voltage_level() -> float
• set_voltage_level(level: float) -> None
• set_voltage_range(level: float) -> None
• set_current_compliance_level(level: float) -> None
• compliance_tripped() -> bool

After final ramp-to-zero measure the voltage on the source terminal until voltage settled to zero (current threshold |0.5| V).

Supported instruments are Keithely 2410, 2470 and 2657A.

Add remote control using an embedded micro TCPIP server and JSON protocol.

Proposal using JSON-RPC protocol via TCP socket:

Start notification.

{"jsonrpc": "2.0", "method": "start", "id": 0}

Stop notification.

{"jsonrpc": "2.0", "method": "stop", "id": 0}

Change voltage notification.

Applies only during continuous It measurement.

Requires parameter end_voltage and optional parameters step_voltage
(default is 1.0 Volt) and waiting_time (default is 1.0 seconds).

{"jsonrpc": "2.0", "method": "change_voltage", "params": {"end_voltage": 100.0, "step_voltage": 10.0, "waiting_time": 0.25}, "id": 0}

State snapshot.

{"jsonrpc": "2.0", "method": "state", "id": 0}

This will return application state parameters.

{"jsonrpc": "2.0", "result": {"measurement_type": "iv", "sample": "VPX1", "source_voltage": 24.0, "smu_current": 0.0025, "elm_current": 0.0021, "lcr_capacity": null, "temperature": 24.031}, "id": 0}

Add an option to save also a screenshot of the displayed plots at the end of a measurement (together with the measurement data file).

Add route terminals option for Keithely 2410 and 2470 SMUs to switch between front/rear terminals.

:ROUTe:TERMinals (FRON|REAR)

Add support for 3-channel HV-switch (Brand Box) to close selected relays on start of measurement and release after measurement.

Toggle zero check for K6214 and K6217B electrometers off before measurement and back on after finishing the measurement.

A range of Keithley Instruments (2410, 6514, 6517B) do not support a filter (average) count of 1 although the valid range in the User Manuals is defined as 1...100. Setting the value to 1 creates an Invalid Parameter error in the queue.

It was proposed to limit the input range to 2...100.

Add support for LCR meter Agilent 4284A

To increase the performance for fast measurements (waiting time = 0) polling for compliance tripped can be limited to once every second (no need to poll multiple times per second in case of fast measurements).

An LCR measurement x of value zero crashes the application applying the formula: 1. / x ** 2 due to an unhandled DivisionByZeroError exception.

Validate that the measured value is not zero, else ignore and do not add to the plot.

Using change voltage to reduce the voltage during It measurements yields a range error due to the fact that the source range is set to the target voltage before ramping down.

Change voltage needs two strategies: increase voltage and decrease voltage, eg. (pseudo code)

def increase_voltage(current_voltage, target_voltage, step_voltage):
    context.set_source_range(target_voltage)  # set higher target range
    for voltage in linear_range(current_voltage, target_voltage, step_voltage):
        context.set_source_voltage(voltage)

def decrease_voltage(current_voltage, target_voltage, step_voltage):
    for voltage in linear_range(current_voltage, target_voltage, step_voltage):
        context.set_source_voltage(voltage)
    context.set_source_range(target_voltage)  # set lower target range

def change_voltage(current_voltage, target_voltage, step_voltage):
    if abs(current_voltage) > abs(target_voltage):
        decrease_voltage(current_voltage, target_voltage, step_voltage)
    else:
        increase_voltage(current_voltage, target_voltage, step_voltage)

Es wäre hilfreich, in der Status bar unten die loop-Zeit (Messzeit) anzuzeigen, um minimale "Waiting Time" herauszufinden. Sowohl für IV als auch für IT.
(Hintergrund: Es gibt Leute, die stellen eine Waiting time von 0.1 sec ein und wundern sich, warum nicht alle zehntel Sekunde eine Messung passiert..)

Invalid plot values (None, NaN, +inf, -inf) from either measurement or data file can cause application crashes as plots can only accept finite float values.

Use math.nan as defaults for dictionary keys (avoiding None) and math.isfinite(x) to verify if the value can be added to a plot.

In addition it would beneficial to refactor class PlotsController into independent classes IVPlotsController and CVPlotsController for better modularization.

To make it more convenient to switch between instruments of the same role (ie. SMU), resource settings and parameters should be persistent for every model independently.

File permission error exceptions are not handled and result in application crashes.

The cause seems to be connecting the file writer methods using Qt signals while executing the measurement in another thread. A workaround might be to add a simple callback mechanism to the measurement object (avoiding using Qt signals and executing file writer operations in the measurement thread).

Add DMM (digital multi-meter) role to enable reading temperature, supporting Keithley K2700.

The DMM has to be configured manually by the user to provide readings in degC, no reset by software.

Operating old instruments (K237) using GPIB bus yields sporadic connection losses during measurements (VISA invalid resource identifier).

To overcome this problem the instrument resource should provide an auto-reconnect-and-retry feature that closes the current connection and opens a new connection end repeats the query in case of an connection related error.

I am not sure if this issue/request got lost or I reported it only in slack, but with the Keithley 2470 we do not get display updates of voltage/current on the device's internal screen during ramp-down.

When using the tool in conjunction with a Keithley 2470 source meter, the precision of the timestamp is insufficient. The Keithley 2470 measures 100 samples or more per second. However, writer.py only uses timestamps with a precision of 10ms (safe_format(data.get('timestamp'), '.2f')). This leads to multiple sampes having the same timestamp. Timestamps with ms or µs precision would be preferrable.

Setup:

1. sim SMU: python -m comet.emulator.keithley.k2410 -p 11002
2. on start the communication works:

INFO:root:send (54, 'b'Spanish Inquisition Inc., Model 2410, 43768438, v1.0\r\n'')
INFO:root:recv (13, 'b':OUTP:STAT?\r\n'')
INFO:root:send (3, 'b'0\r\n'')
INFO:root:recv (26, 'b':SOUR:VOLT:LEV 0.000E+00\r\n'')
INFO:root:recv (7, 'b'*OPC?\r\n'')
INFO:root:send (3, 'b'1\r\n'')
INFO:root:recv (6, 'b'*CLS\r\n'')
INFO:root:recv (7, 'b'*OPC?\r\n'')
INFO:root:send (3, 'b'1\r\n'')
INFO:root:recv (17, 'b':ROUT:TERM FRON\r\n'')
INFO:root:recv (7, 'b'*OPC?\r\n'')
INFO:root:send (3, 'b'1\r\n'')
INFO:root:recv (24, 'b':SOUR:FUNC VOLT\r\n*OPC?\r\n'')
INFO:root:send (3, 'b'1\r\n'')
INFO:root:recv (33, 'b':SENS:CURR:AVER:TCON MOV\r\n*OPC?\r\n'')
...

1. The exception occurs at some time after the start command (few secs):

2022-05-09T09:50:20::diode_measurement.measurement::ERROR::K2470: TCPIP0::localhost::11002::SOCKET: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.
Traceback (most recent call last):
  File "diode_measurement\resource.py", line 56, in read
  File "pyvisa\resources\messagebased.py", line 486, in read
  File "pyvisa\resources\messagebased.py", line 442, in _read_raw
  File "pyvisa_py\highlevel.py", line 519, in read
  File "pyvisa\highlevel.py", line 251, in handle_return_value
pyvisa.errors.VisaIOError: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "diode_measurement\driver\driver.py", line 12, in handle_exception
  File "diode_measurement\driver\k2470.py", line 76, in _query
  File "diode_measurement\resource.py", line 43, in query
  File "diode_measurement\resource.py", line 60, in read
diode_measurement.resource.ResourceError: TCPIP0::localhost::11002::SOCKET: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "diode_measurement\measurement\__init__.py", line 110, in run
  File "diode_measurement\measurement\__init__.py", line 328, in measure
  File "diode_measurement\measurement\iv.py", line 54, in acquireReading
  File "diode_measurement\measurement\iv.py", line 34, in acquireReadingData
  File "diode_measurement\driver\k2470.py", line 64, in read_current
  File "diode_measurement\driver\driver.py", line 14, in handle_exception
diode_measurement.driver.driver.DriverError: K2470: TCPIP0::localhost::11002::SOCKET: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.
2022-05-09T09:50:24::diode_measurement.measurement::ERROR::K2470: TCPIP0::localhost::11002::SOCKET: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.
Traceback (most recent call last):
  File "diode_measurement\resource.py", line 56, in read
  File "pyvisa\resources\messagebased.py", line 486, in read
  File "pyvisa\resources\messagebased.py", line 442, in _read_raw
  File "pyvisa_py\highlevel.py", line 519, in read
  File "pyvisa\highlevel.py", line 251, in handle_return_value
pyvisa.errors.VisaIOError: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "diode_measurement\driver\driver.py", line 12, in handle_exception
  File "diode_measurement\driver\k2470.py", line 76, in _query
  File "diode_measurement\resource.py", line 43, in query
  File "diode_measurement\resource.py", line 60, in read
diode_measurement.resource.ResourceError: TCPIP0::localhost::11002::SOCKET: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "diode_measurement\measurement\__init__.py", line 118, in run
  File "diode_measurement\measurement\__init__.py", line 365, in finalize
  File "diode_measurement\measurement\__init__.py", line 354, in read_source_voltage
  File "diode_measurement\driver\k2470.py", line 67, in read_voltage
  File "diode_measurement\driver\driver.py", line 14, in handle_exception
diode_measurement.driver.driver.DriverError: K2470: TCPIP0::localhost::11002::SOCKET: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.

Migrating from unittest to pytest for enhanced unit testing.

QDateTime.fromMSecsSinceEpoch raises a TypeError one some occasions albeit the assigned float value is cast to an integer.

TypeError: arguments did not match any overloaded call:
  fromMSecsSinceEpoch(int): argument 1 has unexpected type 'float'
  fromMSecsSinceEpoch(int, Qt.TimeSpec, offsetSeconds: int = 0): argument 1 has unexpected type 'float'
  fromMSecsSinceEpoch(int, QTimeZone): argument 1 has unexpected type 'float'

This issue seems to affect only on Windows OS.

Make it possible to change source voltage during It measurements by applying a configurable ramp to a new target voltage level.

• add button Change Voltage to Continuous Meas. group box in General tab.
• create a Change Voltage dialog to configure ramp parameters end voltage, step voltage and waiting time.

Add automatic source voltage range selection for ramps and when changing continuous measurement voltage.

Triggering change voltage results in a NameError exception ('IVMeasurement' object has no attribute 'itReading'.).

Show only IV or CV plots depending on selected measurement type (instead of tab widget).

A unit conversion error due to non English locales using pint returns waiting times scales by a factor of 1000.

Quick fix: do not scale waiting time using pint.

A misspelled attribute prevents starting measurements (pylint, flake8 and mypy failed to detect the issue).

CV measurement's 1/c^2 plot is not cleared when starting a new measurement.

Also the y axis label should show 1/F^2 (not pF).

the title says it all. The feeling is also that it lasts much longer on the first start after the software was opened. But even later it takes several seconds until something happens after the start button was pressed.

If it is intentional then it needs to be written somewhere how long this delay lasts.
If it is not intentional then we need to investigate why it takes so long.

Raise dedicated error message if a selected instrument's resource name is empty.

If an error occurs during a measurement the corresponding error dialog shows up after ramping down and finishing the measurement.

The dialog should show up immediately.

For K6514 and K6517B add panel inputs for

• current auto range
• current range
• average state
• average count
• average tcontrol
• power line cycles (NPLC)

A request for adding following options for LCR meters 4284A and 4980A:

• Correction
  • Enable SHORT
• AC Voltage
  • Amplitude (mV)
  • Frequency (Hz)
  • ALC (Auto Level Control)

Add NPLC input for SMUs to set measurement integration time/aperture.

For K2410 and K2470 (0.01 to 10) configure :SENS:CURR:NPLC <n>

For K2657A (0.001 to 25) configure smuX.measure.nplc = <n>