# Lock-in Amplifier

This instrument features a dual-phase demodulator with cascaded single pole low-pass filters to attenuate the second harmonic and suppress noise in each quadrature

If you are directly using the RESTful API (e.g. using cURL), the instrument name as used in the URL is lockinamp.

# Configuration guide

The Lock-in Amplifier configuration is made up of the:

Demodulation source (set with set_demodulation),
Auxiliary output (set with set_aux_output and set_outputs), and
PID controller (set with use_pid and set_by_frequency).

A recommended workflow is to set the main, auxiliary, and PID controller settings, then connect the sources to an output with set_outputs last, as each selection can change the available options. Read more about the possible options in the set_outputs.

Set strict=False to move between incompatible configurations, this will coerce the instrument into the unsetting other values as required, read more about strict coercions. For example, when moving from using the PID controller in filtered signal mode (outputting both R and Theta or X and Y signals) to another configuration (setting Main output as R and Aux output as Aux).

Lock-in Amplifier configuration
├─── demodulation source  # Select the main demodulation source
|   ├── Internal              i.set_demodulation(mode="Internal")
|   ├── External              i.set_demodulation(mode="External")
|   ├── External PLL          i.set_demodulation(mode="External PLL")
|   └── None                  i.set_demodulation(mode="None")
|
├── auxiliary output     # Select what the signal connected to the auxiliary output
|   ├── Auxiliary oscillator      i.set_aux_output(frequency=1000, amplitude=1)
|   |                             i.set_outputs(main="X", aux="Aux")
|   |
|   ├── Demodulation              i.set_demodulation(mode="Internal", frequency=1000)
|   |                             i.set_outputs(main="X", aux="Demod")
|   |
|   └── Filtered signal           i.set_outputs(main="X", aux="Y")
|
└── PID controller       # Attach a PID controller to the main or auxiliary outputs
    ├── Off                       i.use_pid("Off")
    |
    ├── Main                      i.use_pid("Main")
    |                             i.set_by_frequency(prop_gain=-10)
    |
    └── Aux                       i.set_demodulation(mode="Internal")
                                  i.set_outputs(main="X", aux="Y")
                                  i.use_pid("Aux")
                                  i.set_by_frequency(prop_gain=-10)

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Functions

Core

Multi-instrument: Lock-in Amplifier in multi-instrument context
getters: Lock-in Amplifier - getter functions
load_settings: Load a previously saved `.mokuconf` settings file into the instrument. To create a `.mokuconf` file, either use `save_settings` or the desktop app.
save_settings: Save instrument settings to a file. The file name should have a `.mokuconf` extension to be compatible with other tools.
set_aux_output: Configures the Auxiliary sine wave generator
set_defaults: Reset the Lock-in Amplifier to its default state
set_demodulation: Configures the demodulation source and optionally its frequency and phase
set_filter: Configures the LIA low-pass filter
set_frontend: Configures the input impedance, coupling, gain, and attenuation for each channel.
set_gain: Sets output gain levels
set_outputs: Configures output sources and offsets
set_polar_mode: Sets the range of the signal input to the Polar conversion block.
summary: Returns a short summary of current instrument state

Data Logger

logging_progress: Returns current logging state.
start_logging: Start the data logging session to file.
stop_logging: Stops the current instrument data logging session.

Data Streaming

get_chunk: Get a single chunk out of data stream
get_stream_data: Get the converted data stream
getters: Lock-in Amplifier - Streaming - getter functions
start_streaming: Start a streaming session
stream_to_file: Save the streaming session to a file
stop_streaming: Stops the current instrument data streaming session.

Input PLL

pll_reacquire: Triggers a reacquisition cycle on the embedded PLL
set_pll: Sets the frequency acquisition/configuration and tracking bandwidth of the PLL.

Oscilloscope

enable_rollmode: Enables and disables Roll Mode X-axis behaviour
get_data: Get a frame of the data from the instrument
getters: Lock-in Amplifier - Oscilloscope - getter functions
save_high_res_buffer: Save the high resolution channel buffer data to a file on the Moku's internal storage
set_acquisition_mode: Set acquisition mode
set_hysteresis: Configures the hysteresis around trigger point.
set_timebase: Set the left- and right-hand span for the time axis. Units are seconds relative to the trigger point.
set_trigger: Sets trigger source and parameters.
set_monitor: Configures the specified monitor channel to view the desired Lock-in Amplifier probe point signal.

PID Controller

set_by_frequency: Configure the embedded PID controller using crossover frequencies
use_pid: Enables and disables a PID controller on either the Main or Aux outputs

Multi-instrument Context →