Data Acquisition Reference Application for LabVIEW

The Data Acquisition Reference Application for LabVIEW is a specific application implementation based on the framework defined in the Data Acquisition Reference Design. This application uses the FlexSignal Reference Library to acquire data from DAQmx devices, TDMS files, or simulated signals. The data can be logged to TDMS files and viewed in several different displays such as a power spectrum, harmonic cursor, and RMS chart. The Channel Monitor XControl is used as a general channel monitoring tool to show overall level and time domain signals.

This is the top-level Project Library and contains the main application.  It also holds the System Configuration.ctl type definition.  

The best place to start with customizing the code is with the System Configuration type definition.  This type definition contains information that will be used by most of the other Project Libraries.  Any changes here will be propagated to them.  Add the data types that you think you’ll need for data acquisition and data logging.

The GUI of the main application consists of a toolbar of icons for actions and the Channel Monitor XControl. 

Figure 1 - GUI of main application

The Channel Monitor XControl gives the user another way to interact with the data as well as some feedback to the applied configuration settings and if the acquisition is active. 

Consider the most appropriate default data view for the application and use it in the main GUI.

The Analog Input [FlexSignal] Project Library is the acquisition engine of the application.  In this case, the acquisition source is the FlexSignal Reference Library which can acquired data from DAQmx devices, TDMS files, or simulated signals.  The main VI of the Project Library is “DAQ Analog Input.vi”.  This VI is an action engine with three states: Configure and Start, Read, and Close.

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Figure 2 - DAQ Analog Input.vi block diagram

This VI contains all of the specific acquisition code.  To change or modify the way the data is acquired, change this code.

The DAQ AI Engine State.vi receives messages generated by user events (such as pressing the Start button) and translates it into the appropriate next state for the DAQ process.  This VI does not need to be modified unless the states or commands for the DAQ process are changed.

The other VIs (Get AI Channel Names and Get AI Input Range) are helper VIs used to setup the Channel Monitor XControl.

This is the VI to modify if you want to change the file type, file naming convention or add other application information to the log file such as test run, user, hardware settings, etc.

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Figure 3 - TDMS Data Logging.vi block diagram

The TDMS Log Engine State.vi receives messages generated by user events (such as pressing the Log button) and translates it into the appropriate next state for the Logging process.  This VI does not need to be modified unless the states or commands for the Logging process are changed.