How to transition from a VI Logger Task to a LabVIEW SignalExpress project ?

Overview

LabVIEW SignalExpress is the newest member of the LabVIEW family, and replaces VI Logger as National Instruments’ premier data logging solution.  LabVIEW SignalExpress now offers a more complete spectrum of features, including data export, report generation, alarms & events, real-time documentation updates, and increased hardware support. With detailed help and intuitive steps, you can quickly configure your logging task to easily acquire, log, view, and share your data.  This data logging software solution is tightly integrated with the LabVIEW development environment, enabling LabVIEW SignalExpress tasks to be easily converted into LabVIEW code for more flexibility and precise configuration. 

This tutorial highlights the steps involved in creating a task using VI Logger and the equivalent process using LabVIEW SignalExpress with the same acquisition and timing parameters. If you already have VI Logger datalogs and are interested in using them in LabVIEW SignalExpress, the VI Logger Migration tutorial  explains how to convert datalogs to Technical Data Management Streaming (TDMS) which you can access in LabVIEW SignalExpress.

VI Logger Task

This section describes how to create a VI Logger task to acquire simulated data . The rest of this tutorial assumes that you have a Data Acquisition device installed on your computer or that you have created an NI-DAQmx Simulated Device.

1. Create an NI-DAQmx task inside VI Logger using the DAQ Assistant.

1. Open Measurement &Automation Explorer (MAX). Expand My System tree, Right-Click on VI Logger Tasks and select Create New…
2. Select Using NI-DAQmx and click Finish and the VI Logger Setup page appears.
   
   
   
   

   Figure 1. VI Logger Setup Page.

3. On the VI Logger Setup page, click on Create New... to create a new NI-DAQmx task.
4. A window prompts you to select the measurement type. Select Acquire Signals » Acquire Input » Voltage as the measurement type for this task.
   
   

   

   Figure 2. Step 1 of the DAQ Assistant: Select a measurement type.

5. Click Next and  a window prompts you to select the physical channels. Select ai0 and ai1 from the list of supported physical channels.
   
   
   

   Figure 3. Step 2 of the DAQ Assistant: Select the physical channels.

6. Click Next. The DAQ Assistant prompts you to give your task a descriptive name. The default is: "MyVoltageTask".  
7. Click Finish and configure the resulting window as shown below for both analog channels. Click OK when done.
   

Figure 4. Task Configuration Window.

2. Use the NI-DAQmx Task to complete a data logging application.

1. Since MyVoltageTask is selected by default as the NI-DAQmx Task Name in the Acquisiton Settings, click Run task in the toolbar to start acquiring data.
   
   

   

   Figure 5. VI Logger Task Output.

2. Once you have acquired your data, you can click on View in Excel in the toolbar to export the data to Microsoft Excel.

LabVIEW SignalExpress Project

This section describes how to create the LabVIEW SignalExpress project

1. Open LabVIEW SignalExpress by going to Start » Programs » National Instruments » LabVIEW SignalExpress.

2. Create a step to acquire data

1. Click the Add Step button below the menu options to place the first step in the project.
2. Select Acquire Signals » DAQmx Acquire » Analog Input » Voltage as the measurement type.
   
   

   

   Figure 6. Acquire Signals Step.

3. Select ai0 and ai1 from the list of supported physical channels and click OK. Configure the resulting window as shown below.  

Figure 7. LabVIEW SignalExpress: Task Configuration Window.

3. Click on the Run Once button to acquire the finite samples.

4. To view the data, click on the Data View tab and drag the signal into the graph display. If you drag the entire step, you     will get a window that looks similar to the Task Configuration Window.

Figure 8. LabVIEW Signal Express: Data Viiew

5. To being logging, click on the Record button in the toolbar. The Logging Signals Selection window appears             and prompts you to select the signals to include in the log. After the selecting both signals, you will see a log appear in the bottom left corner of your LabVIEW SignalExpress project window. Click on the Record button again to stop logging.

Figure 9. Logging acquired data.

LabVIEW SignalExpress Offerings

LabVIEW SignalExpress provides automatic device detection when using National Instruments USB DAQ devices and immediately launches a data-logging application based on the measurement being made. Recording Options, Alarms, Events, Project Documentation, and network-published shared variables support are just some of the many features of LabVIEW SignalExpress. By combining LabVIEW SignalExpress and LabVIEW, you have limitless options for your data-logging applications. You can automatically generate LabVIEW code from your existing LabVIEW SignalExpress projects, allowing you to create custom user interfaces, apply over 600 math, signal processing and analysis functions, as well as distribute your applications as executables.

Currently, LabVIEW SignalExpress does not provide direct support for Traditional NI-DAQ(Legacy), and Fieldpoint devices. This can however, be achieved through the use of shared variables.

Summary

With the addition of LabVIEW SignalExpress, National Instruments now offers a more complete and versatile data logging software solution.  VI Logger logs can be converted to SignalExpress data, easing the migration. Furthermore, this new software provides much needed flexibility, allowing users to integrate acquired data in their LabVIEW applications.

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