Lock-in Amplifiers

This module provides support for controlling lock-in amplifiers with Python. Lock-in amplifiers can be imported by

>>> import hardware
>>> lia = hardware.function_generators.SRS_SR844('GPIB0:...')

class hardware.lock_in_amplifiers.SRS_SR844(visa_search_term)

Hardware wrapper for Stanford Research Systems SR844 Lock-in Amplifier

Parameters:

visa_search_term (str) – The address that is passed to visa.ResourceManager().open_resource()

Variables:

• phase (float) – The phase between the input and the reference signals in radians.
• sensitivity (float) – The sensitivity of the lock-in amplifer in volts.
• time_constant (float) – The time constant for the lock-in amplifier filter.

autogain()

Performs the built-in AGAN function in order to auto-gain the lock-in amplifier.

autophase()

Sends the APHS command to the lock-in over the GPIB bus. This performs the Auto Phase function. This command is the same as pressing Shift−Phase on the lock-in amplifier front panel. This command adjusts the reference phase so that the current measurement has a Y value of zero and an X value equal to the signal magnitude, R.

get_status(status=None, verbose=False)

Gets the status bits using the LIAS? GPIB query. Optionally, status bits can be provided and interpreted.

Parameters:

• status (str, optional) – Status bits to decode. If not supplied, the status bits will be read from the lock-in amplifier.
• verbose (bool) – Explains the status bits if True

Returns:

str – Status bits in binary form.

identify()

Returns:str – The response from an *IDN? GPIB query.