keithley2600 1.2.2

Full Python driver for the Keithley 2600 series.

keithley2600

A full Python driver for the Keithley 2600 series of source measurement units.

About

Keithley driver with access to base functions and higher level functions such as IV measurements, transfer and output curves, etc. Base commands replicate the functionality and syntax from the Keithley's internal TSP functions, which have a syntax similar to Python.

Warning:

There are currently only heuristic checks for allowed arguments in the base commands. See the Keithley 2600 reference manual for all available commands and arguments. Almost all remotely accessible commands can be used with this driver. Not supported are:

• lan.trigger[N].connected: conflicts with the connected attribute of Keithley2600Base.
• io.output(): conflicts with smuX.source.output attribute
• All Keithley IV sweep commands. We implement our own in the Keithley2600 class.

Usage

Connect to the Keithley 2600 and perform some base commands:

>>> from keithley2600 import Keithley2600
>>> k = Keithley2600('TCPIP0::192.168.2.121::INSTR')
>>> k.smua.source.output = k.smua.OUTPUT_ON   # turn on SMUA
>>> k.smua.source.levelv = -40  # sets SMUA source level to -40V
>>> volts = k.smua.measure.v()  # measures and returns the SMUA voltage
>>> i = k.smua.measure.i()  # measures current at smuA
>>> k.smua.measure.v(k.smua.nvbuffer1)  # measures the voltage, stores the result in buffer
>>> k.smua.nvbuffer1.clear()  # clears nvbuffer1 of SMUA

Higher level commands defined in the driver:

>>> data = k.readBuffer(k.smua.nvbuffer1)  # reads all entries from nvbuffer1 of SMUA
>>> errs = k.readErrorQueue()  # gets all entries from error queue

>>> k.setIntegrationTime(k.smua, 0.001)  # sets integration time in sec
>>> k.applyVoltage(k.smua, 10)  # turns on and applies 10V to SMUA
>>> k.applyCurrent(k.smub, 0.1)  # sources 0.1A from SMUB
>>> k.rampToVoltage(k.smua, 10, delay=0.1, stepSize=1)  # ramps SMUA to 10V in steps of 1V

>>> # sweep commands
>>> k.voltageSweepSingleSMU(k.smua, list(range(0, 61)), t_int=0.1,
...                         delay=-1, pulsed=False)
>>> k.voltageSweepDualSMU(smu1=k.smua, smu2=k.smub, smu1_sweeplist=list(range(0, 61)),
...                       smu2_sweeplist=list(range(0, 61)), t_int=0.1, delay=-1, pulsed=False)
>>> k.transferMeasurement( ... )
>>> k.outputMeasurement( ... )

Singleton behaviour:

Once a Keithley2600 instance with a visa address 'address' has been created, repeated calls to Keithley2600('address') will return the existing instance instead of creating a new one. This prevents the user from opening multiple connections to the same instrument simultaneously and allows easy access to a Keithley2600 instance from different parts of a program. For example:

>>> from keithley2600 import Keithley2600
>>> k1 = Keithley2600('TCPIP0::192.168.2.121::INSTR')
>>> k2 = Keithley2600('TCPIP0::192.168.2.121::INSTR')
>>> print(k1 is k2)
True

Data structures:

The methods voltageSweepSingleSMU and voltageSweepDualSMU return lists with the measured voltages and currents. The higher level commands transferMeasurement and outputMeasurement return ResultTable objects which are very similar to pandas dataframes but add support for column units. ResultTable stores the measurement data internally as a numpy array and provides information about column titles and units. It also provides a dictionary-like interface to access columns by name, live plotting of the data (requires matplotlib), and methods to load and save the data to text files.

For example:

>>> import time
>>> from  keithley2600 import Keithley2600, ResultTable
>>> k = Keithley2600('TCPIP0::192.168.2.121::INSTR')
>>> # create ResultTable with two columns
>>> rt = ResultTable(column_titles=['Voltage', 'Current'], units=['V', 'A'],
...                  params={'recorded': time.asctime(), 'sweep_type': 'iv'})
>>> # create live plot which updates as data is added
>>> rt.plot(live=True)  
>>> # measure some currents
>>> for v in range(0, 20):
>>>     k.applyVoltage(k.smua, 10)
...     i = k.smua.measure.i() 
...     rt.append_row([v, i])
>>> # save and plot the data
>>> rt.save('~/iv_curve.txt')

See the documentation for all available methods.

Installation

Install the stable version from PyPi by running

$ pip install keithley2600

or the latest development version from GitHub:

$ pip install git+https://github.com/OE-FET/keithley2600

Documentation

See the Keithley 2600 reference manual here for all available commands and arguments.