Externally Verify Reading and Writing Values of a Multifunction DAQ

Updated Jan 20, 2023



  • Multifunction I/O Device
  • PXI Multifunction I/O Module
  • C Series Multifunction I/O Module


  • Measurement & Automation Explorer (MAX)
  • LabVIEW


  • NI-DAQmx

How can I verify my multifunction DAQ card is reading or writing the correct value?

An external loopback test will verify with a known source whether an output or input channel is working properly.  Follow the steps below to perform an external loopback test.
  1. Wire AI x to AO y.  The device pinouts can be found in Measurement & Automation Explorer (MAX) by right-clicking the device, as shown in figure below.
  1.  Open Cont Acq&Graph Voltage-Int Clk. vi from NI Example Finder, as shown in figure below. In LabVIEW select Help»Find Examples. From the NI Example Finder window, select Hardware Input and Output»DAQmx»Analog Measurements»Voltage»Cont Acq&Graph Voltage-Int Clk. vi. This example will read the analog input channel.
  1. Open a test panel in MAX. A test panel can be opened by right-clicking the device or selecting Test Panels from the toolbar, as shown in figure below.
  1. Configure the test panel for the analog output channel, as shown in figure below. Select Run to generate a signal from AO y.
  1. Run the Cont Acq&Graph Voltage-Int Clk. vi and verify the signal appears as expected, as in figure below.