The Moku:Go Data Logger instrument records time series voltages from one or two channels at rates from 10 samples per second up to 1 MSa/s. It allows logging data to onboard storage or streaming directly to a computer using the Moku API. The Moku:Go Data Logger also includes a two-channel embedded waveform generator.

Version: V23-0127

For more information, visit: liquidinstruments.com

User Interface Overview

The Moku:Go interface displays various elements for controlling and monitoring the data logger. Key components include:

• Main menu: Accessed via the [menu icon] in the top-left corner.
• Save data: Function to save current data or settings.
• Screen navigation: Controls for moving around the display.
• Settings: Access to instrument configuration options.
• Settings pane: Displays detailed settings.
• Waveform generator: Controls for the built-in waveform generator.
• Storage indicator: Shows available storage space.
• Start logging: Button to begin data recording.
• Status indicator: Displays the current operational status.
• Cursors: Tools for measuring specific points on the signal display.
• Zoom-out preview: A small view showing the overall signal range.

Main Menu

The main menu, accessed by the [menu icon] in the top-left corner, provides access to various functions:

• My devices: Return to device selection.
• Switch instruments: Switch to another instrument.
• Save/recall settings: Save or load instrument settings.
• Reset instrument: Reset the instrument to its default state (Shortcut: Ctrl+R).
• Power supply: Access the Power Supply control window (available on M1/M2 models).
• File manager: Open the File Manager tool.
• File converter: Open the File Converter tool.
• Help: Access resources like the Liquid Instruments website, shortcuts list (Shortcut: Ctrl/Cmd+H), manual (Shortcut: F1), report an issue, and About information.

Signal Display Navigation

The signal display allows for detailed viewing and analysis of recorded data.

Signal Display Position

The displayed signal can be moved by clicking and dragging anywhere on the display window. The cursor changes to a [move icon] when active. Drag horizontally to shift along the time axis and vertically to shift along the voltage axis. The arrow keys can also be used for fine adjustments.

Display Scale and Zoom

Users can zoom in and out using the scroll wheel or trackpad gestures. Scrolling zooms the primary axis, while holding Ctrl/Cmd and scrolling zooms the secondary axis. The [axis icon] allows selection of the primary/secondary axis. A rubber band zoom feature is available by clicking and dragging left-to-right to zoom into a selected region, or right-to-left to zoom out.

Keyboard Zoom Controls:

• Ctrl/Cmd + Scroll Wheel: Zooms the secondary axis.
• +/-: Zooms the primary axis using the keyboard.
• Ctrl/Cmd +/-: Zooms the secondary axis using the keyboard.
• Shift + Scroll Wheel: Zooms the primary axis towards the center.
• Ctrl/Cmd + Shift + Scroll Wheel: Zooms the secondary axis towards the center.
• R: Activates rubber band zoom.

Auto Scale

Double-clicking anywhere on the signal display automatically scales the trace's vertical (voltage) axis.

Settings

The controls options, accessed via the [settings icon], reveal the control drawer for instrument settings, including analog front-end and data acquisition settings.

Analog Front-end Settings

Configure input channels for voltage range and coupling:

• Input 1 / Input 2:
• Coupling: Switchable AC/DC coupling. DC coupling is preferred for most applications as it does not filter the signal. AC coupling acts as a high-pass filter, useful for signals with large DC offsets.
• Range: Selectable voltage ranges, such as 10 Vpp or 50 Vpp.

Data Acquisition Settings

Configure data acquisition parameters:

Waveform Generator

The Moku:Go Data Logger features a built-in Waveform Generator capable of producing basic waveforms on its two output channels. For detailed instructions, refer to the Moku:Go Waveform Generator manual.

The interface allows selection of waveform types (e.g., Sine, Ramp) and configuration of parameters like frequency, coupling, and range for each output channel.

Cursors

Cursors can be added to the signal display to measure specific points. Access cursors via the [cursor icon]. Drag horizontally for time cursors, vertically for voltage cursors. All cursors can be removed from this menu.

Cursor Types and Functions

Time Cursor Options:

• Attach to trace: Attaches the time cursor to a specific input channel (Input 1 or Input 2), turning it into a tracking cursor that provides continuous voltage readings at the cursor's time.
• Reference: Sets the cursor as a reference point.
• Remove: Deletes the time cursor.

Tracking Cursor Options:

• Channel: Assigns the tracking cursor to a specific channel.
• Detach from trace: Detaches the tracking cursor from its assigned channel.
• Remove: Deletes the tracking cursor.

Voltage Cursor Options:

• Manual: Manually set the vertical position of the cursor.
• Track mean: Tracks the mean voltage.
• Track maximum: Tracks the maximum voltage.
• Track minimum: Tracks the minimum voltage.
• Maximum hold: Sets the cursor to hold at the maximum voltage level.
• Minimum hold: Sets the cursor to hold at the minimum voltage level.
• Channel: Assigns the voltage cursor to a specific channel.
• Reference: Sets the cursor as a reference point.
• Remove: Deletes the voltage cursor.

Additional Tools

The Moku:Go app includes file management tools for data handling.

File Manager

The File Manager allows downloading saved data from Moku:Go to a local computer. It supports optional file format conversion. After a file is transferred, a [file icon] appears next to it.

File Converter

The File Converter tool converts Moku:Go binary (.li) files on the local computer to other formats such as CSV, MATLAB (.mat), or NumPy (.npy). Converted files are saved in the same folder as the original file.

File Converter Menu Options:

• File: Open file (Ctrl/Cmd+O) to select a .li file for conversion; Open folder (Ctrl/Cmd+Shift+O) to select a folder; Exit to close the window.
• Help: Access the Liquid Instruments website, report an issue, or view About information.

Power Supply

The Moku:Go Power Supply is available on M1 (two-channel) and M2 (four-channel) models. It operates in two modes: Constant Voltage (CV) or Constant Current (CC). Users can set current and voltage limits for each channel. The Power Supply operates at the set current or voltage limit, whichever is met first.

Power Supply Functions:

Instrument Reference

Recording a Session

To record data:

1. Configure channels, voltage range, coupling, and impedance. Use the plotter window to verify signal connection.
2. Configure acquisition rate and mode (Normal or Precision).
3. Set recording duration and add any comments.
4. Optionally configure waveform generator outputs.
5. Tap "record" to start.

Configuring Inputs

Moku:Go features switchable AC/DC coupling on each input, accessible from the channels tab. DC coupling is standard. AC coupling acts as a high-pass filter, removing DC components and useful for signals with large DC offsets.

Acquisition Modes and Sampling

Data acquisition involves acquiring data from ADCs, down-sampling, and storing it in memory, aligned to a trigger point. Sampling methods affect precision and aliasing behavior.

• Normal Mode: Data is removed (direct down-sampling), potentially causing aliasing but providing a viewable signal across all timespans.
• Precision Mode: Data is averaged (decimation) to increase precision and prevent aliasing. However, unsuitable time spans can lead to averaged-out signals.
• Peak Detect Mode: Similar to Precision Mode, but displays the peak (highest and lowest) samples instead of averages.

File Types

Moku:Go can save data in standard CSV format, including instrument settings and comments in the header. It also uses a proprietary binary format (.li) optimized for speed and size, allowing high logging rates and low memory usage. The File Converter can convert binary files to CSV, MATLAB, or NPY formats.

Starting the Log

Tap the red record button to start logging. The status indicator shows progress. The log stops when the duration is reached or the record button is tapped again.

Data Streaming

The Data Logger can stream data over a network via the Moku API, instead of saving directly to the device. More information is available in the API documents at apis.liquidinstruments.com.