LIQUID INSTRUMENTS Moku Lab LabVIEW API Migration User Guide

LIQUID INSTRUMENTS Moku Lab LabVIEW API Migration User Guide

Overview

Moku: Lab software version 3.0 is a major update that brings new firmware, user interfaces, and APIs to Moku:Lab hardware. The update brings Moku:Lab in line with Moku:Fro and Moku:Go, making it easy to share scripts across all Moku platforms. The update unlocks a host of new features to many of the existing instruments. it also adds two new features: Muti-instrument Mode and Moku Cloud Compile. There are some subtle behavioral differences as well outlined in the Backward compatibility section.

This update also affects the APl architecture, and therefore the new API package will not be backwards compatible with existing APl scripts. APlusers will need to port their scripts to the new Moku APl package if they upgrade their Moku:Lab to version 3.C. API users with significant custom software development should carefully consider the level of effort required to port their existing coce. Moku:Lab 1.9 is not recommended for new deployments and all customers are encouraged to upgrade. Eventually, Moku:Lab version 1.9 will lose support, in accordance with our End-of-Life Policy. If issues arise after upgrading, userswill have the option to downgrade to software version 19.

This migration guide outlines advantages of updating and potential complications of updating to Moku:Lab version 3.0. It also outlines the process to upgrade the LabVIEW APl and how to downgrade your Moku:Lab if necessary.

Version 3.0 new features

New features
Software version 3.0 brings Multi-Instrument Mode and Moku Cloud Compile to Moku:Lab for the first time, as well as many performance and usability upgrades across the suite of instruments.

Multi-instrument Mode
Muli-instrument Mode on Moku:Lab allows users to deploy two instruments simultaneously to create a custom test station. Each instrument has full access to the analog inputs and outputs, along with interconnections between instrument slots. The interconnections between instruments support high-speed, low-latency, real-time digital communication up to 2 Gb/s, so instruments can run independently or be connected to build advanced signal processing pipelines. Users can dynamically swap Instruments in and out without interrupting the other adjacent. Advanced users can also deploy their own custom algorithms in Multi-instrument Mode using Moku Cloud Compile.

Moku Cloud Compile
Moku Cloud Compile allows you to deploy custom digital signal processing (DSP) directly onto the Moku:Lab FPGA in Multi-instrument Mode. Write code using a web browser and compile it in the cloud;then use Moku Cloud Compile to deploy the bitstreamto one or more target Moku devices.

Oscilloscope

• Deep memory mode — save up to 4M samples per channel at the full sampling rate (500 MSa/s)

Spectrum Analyzer

• Improved noise floor
• Logarithmic Vrms and Vpp scale
• Five new window functions (Bartlett, Hamming, Nuttall, Gaussian, Kaiser)

Phasemeter

• Users can now output frequency offset, phase, and amplitude as analog voltage signals
• Users can now add DC offset to output signals
• The phase-locked sine wave output can now be frequency multiplied up to 250x or divided down to 0.125x
• Improved bandwidth (1 Hz to 100 kHz)
• Advanced phase wrapping and auto-reset functions

Waveform Generator

• Noise output
• Pulse width modulation (PWM)

Lock-in Amplifier (LIA)

• Improved performance of low-frequency PLL locking
• The minimum PLL frequency has been decreased to 10 Hz
• The internal PLL signal can now be frequency multiplied up to 250x or divided down to 0.125x for use in demodulation
• 6-digit precision for phase values

Frequency Response Analyzer

• Increased maximum frequency from 120 MHz to 200 MHz
• Increased maximum sweep points from 512 to 8192
• New Dynamic Amplitude feature optimizes output signal automatically for best measurement dynamic range
• New In/Int measurement mode
• Input saturation warnings
• The math channel now supports arbitrary complex-valued equations involving the channel signals, enabling new types of complex transfer function measurements
• Users can now measure input signals in dBVpp and dBVrms in addition to dBm
• The progress of the sweep is now displayed on the graph
• The frequency axis can now be locked to prevent accidental changes during along sweep

Laser Lock Box

• Improved block diagram shows scan and modulation signal paths
• New locking stages feature allows users to customize their lock procedure
• Improved performance of low-frequency P_L locking
• 6-digit precision for phase values
• Improved performance of low-frequency P_L locking
• Minimum PLL frequency decreased to 10 Hz
• The PLL signal can now be frequency multiplied up to 250x or divided down to 0.125x for use in demodulation.

OTHER

• Added support for the sinc function to the equation editor which can be used to generate custom waveforms in the Arbitrary Waveform Generator
• Convert binary LI files to CSV, MATLAB, or NumPy formats when downloading from the device

Upgraded API support
The new Moku API package provides enhanced functionality and stability. It will receive regular updates to improve performance and introduce new features.

Backward compatibility limitations

API
The new Moku LabVIEW API package is not backward compatible with the previous Moku:LabLabVIEW API. Inputs and outputs are wholly different. If you have done extensive custom software development utilizing the Moku:Lab LabVIEW API, consider the impact of migrating all your software to be compatible with the new API.

While the Moku:Lab 1.9 LabVIEW API package will no longer receive updates, Liquid Instruments will continue to provide support for users who are unable to migrate to the new API package Find detailed examples for each instrument in the new Moku LabVIEW API package to serve as a baseline for converting prior APl development to the new APl package.

Regressions

RAM disk for data logging
Version 1.9 a had 512 MB filesystem in the device’s RAM, which could be used to log data at high sampling rates. This is no longer available in version 3.0. To enable data logging, an SD card is required. This limits data logging speed to approximately 250 kSa/s for 1 channel and 125 kSa/s for two channels.

Data logging to CSV
Version 1.9 had the ability to save data directly to a CSV file while logging. This feature is not directly available on version 3.0. Users whose workflow included saving CSV files directly to an SD card or the client will now need to first convert the binary file to CSV, either using the client app or by installing the standalone Liquid Instruments File Converter onto the computer they use for data processing.

Non-backwards-compatible changes

Data scaling in LIA
In version 1.9, we implemented data scaling such that multiplying two 0.1V DC signals resulted in a 0.02 V DC output. In version 3.0, we changed this such that the result was 0.01V DC, which is more in line with customers’ intuitive expectations.

Waveform Generator output must be enabled to use as modulation source/trigger
In version 1.9, a different channel’s waveform could be used as a modulation or trigger source in the Waveform Generator, even if that channel’’s output was disabled. This was removed in version 3.0. Users who wantto do cross- modulation without needing to unplug the outputs of their device would need to adjust their workflow.

Moku LabVIEW API

The Moku LabVIEW API package is intended to provide LabVIEW developers the resources needed to control any Moku device and, ultimately, the ability to incorporate these controls into larger end-user applications.

The new Moku LabVIEW API package provides the following:

• Fully functional examples for each instrument.
• A block diagram structure that is easy to understand and can serve as an end user’s starting point for customization and adaptation
• Asetof Vlfunctions providing full control over the Moku device.

Currently supported instruments

1. Arbitrary Waveform Generator
2. Data Logger
3. Digital Filter Box
4. FIR Filter Builder
5. Frequency Response Analyzer
6. Lock-in Amplifier
7. Laser Lock Box
8. Logic Analyzer
9. Oscilloscope
10. Phasemeter
11. Spectrum Analyzer
12. Waveform Generator
13. PID Controller
14. Multi-instrument Mode
15. Moku Cloud Compile

Installation

Requirements

• LabVIEW version 2016 or later
• VIPackage Manager (VIPM)

If you already have a previous version ofthe Moku LabVIEW APlinstalled, please uninstallit before proceeding. You can uninstall the package from the VI package manager by selecling Uninstall Package.

1. Download and install the Moku LabVIEW package from the Liquid Instruments website at
2. The package will install through the VI packet manager. Once complete, you should be able to see the package listed under “installed” in VI Package Manager.
   Figure 1: JKI VI Package Manager
   
   Note: The other packages listed here are dependencies used for data streaming.

Moku API changes

The new Moku LabVIEW APl architecture is sufficiently different from its predecessor and therefore not backwards compatible with existing API scripts. The following simplified Oscilloscope example shows the differences between the legacy and new API packages and serves as a road map for porting existing code.

Oscilloscope example
Figure 2: Oscilloscope APl comparison

Sequence steps

1. Begin Client session and upload Oscilloscope bitstream to Moku
2. Set time base and set the left- and right-hand span for the time axis
3. Generate waveform, configure, and generate a sinewave on channel 1
4. Get data, acquire a single frame of the data from the Oscilloscope.
5. CENITENES
6. End Client session

The sequence described above is a simplified example to illustrate the differences between the legacy and new APl packages. Aside from beginning a client session, uploading an instrument bitstream to Moku, and ending the client session, an end user can exercise any number of functions in various order to meet the needs of their application.

Differences
Here, we look at the differences between the two APIs for each step in the sequence.

1. Begin Maku-Client session and upload Oscilloscope bitstream to Moku
   The new APl has split the client session connection and uploading the instrument bitstream into separate functions, 1A and 1B. All scripts begin with these 2 functions.

2. Settime base
   Instrument functions in the new APl are now single functions. Previously, this was a 2-step process in the legacy API. The first function converts the input parameters lo a JSON string and the seconds function sends the command to the Moku. Additionally, function parameters in the legacy APlwere contained in clusters. The majority of function parameters in the new APl are individual controls.
   Figure 4 Set time base
   

3. Generate waveform
   The generate waveform function is a single function in the new API. In this instance, the function parameters are containedin a cluster. There are several functions in the new AP that require many input parameters; in those instances, a cluster is used.
   

4. Get data
   The get data function is also a single function in the new API. In this instance, the function parameters are individual controls for both APIs. The legacy ARl requires an additional function to convert the output data from the JSON string format into numerical arrays for each channel.
   Figure 7: Close API
   
   

5. End Moku-Client session
   The Close API function is a single function in the new API. All scripts end with this function.
   Figure 7: Close API
   

Palette Comparison
You can find equivalent instrument folders in the Liquid Instruments Moku main palette, seen in Figure 8. Then, in each instrument folder you’ll find the equivalent instrument functions, seen in Figure 9 and Figure 10.
Figure : Main palette, legacy API palette left, new API palette right.

Figure 9: Legacy Oscilloscope instrument folder left, new Oscilloscope instrument folder right.

Figure 10: Instrument functions

The Moku LabVIEW APl is based upon Moku API. For full Moku APl documentation, refer to the Moku API Reference found here https://apisliquidinstruments.com/reference/. Additional details for getting started with Moku LabVIEW API can be found at
https://apis.liquidinstruments.com/starting-labview.html.

Downgrade process

If the upgrade to version 3.0 has provento limit, or otherwise adversely affect, something critical to your application, you can downgrade to the previous version 1.9. This can be done through a web browser.

Steps

1. Contact Liquid Instruments and obtain the file for firmware version 1.9.
2. Type your Moku:Lab IP address into a web browser (see screen shot).
3. Under Update Firmware, browse and select the firmware file provided by Liquid Instruments.
4. SelectUpload & Update. The update process can take more than 10 minutes to complete.
   Figure 11: Downgrade procedure
   

Documents / Resources

| LIQUID INSTRUMENTS Moku Lab LabVIEW API Migration [pdf] User Guide
Moku Lab LabVIEW API Migration, LabVIEW API Migration, API Migration, Migration
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References

• Liquid Instruments
• Moku API Reference | Moku API
• Getting Started with LabVIEW | Moku API

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