Data Acquisition Toolbox™

National Instruments Hardware

• The Data Acquisition Toolbox software requires latest version of the NI-DAQmx drivers. Refer to the Supported Hardware - National Instruments page on the MathWorks website for the latest version of the drivers.

• If you use the Data Acquisition Toolbox software and National Instruments' Measurement and Automation (M&A) Explorer at the same time, a conflict will occur and you will not be able to access your board. To avoid a conflict, you should access your board using either the toolbox or the M&A Explorer, and close the other software application.

• If you install NI-DAQ on your computer, and then install LabVIEW 6i on the same computer, you will need to reinstall NI-DAQ.

• When running a device with a Traditional NI-DAQ driver at a sampling rate of 5000 Hz or higher and with a TransferMode property value of Interrupt, system performance might decline.

• You should configure the SampleRate property with the setverify function just before starting the hardware. Note that the SampleRate value depends on the number of channels added to the device object, and the ChannelSkew property value depends on the SampleRate value.

• When using the 1200 series hardware, you must add channels in reverse order. If you specify invalid channels, the data acquisition engine will create the number of requested channels with valid hardware IDs. You can determine the hardware IDs with the object's display or with the HwChannel property.

• Only one digital I/O (DIO) object should be associated with a given DIO subsystem. To perform separate tasks with the hardware lines, you should add all the necessary lines to the DIO object, but partition them into separate line groups based on the task.

• When using a Traditional NI-DAQ driver, all channels contained within an analog input object must have the same polarity. In other words, the InputRange property for these channels must have all unipolar values or all bipolar values.

• When using mux boards, you must add channels in a specific order using the addmuxchannel function.

• If you have trouble acquiring data with the DAQPad-MIO-16XE-50, you should increase the size of the engine buffer with the BufferingConfig property.

• The ability to use PXI signals in the Data Acquisition Toolbox software is not available. These modes are supported by NI 6281 PXI boards and by the Ni_DAQmx library, but are not available in the toolbox. In particular, the ability to use the PXI_STAR signal for the HwDigitalTriggerSource property of the AnalogInput object and the PXI_CLK10 backplane clock for the ExternalSampleClock property are unavailable.

• Objects created for National Instruments devices, and used with the NI-DAQmx adaptor have the following behavior when you use the GETSAMPLE, PUTSAMPLE, GETVALUE, and PUTVALUE functions:

  • The first time the command is used with the object, the corresponding subsystem of the device is reserved by the MATLAB session.

  • If you then try to access that subsystem in different session of the MATLAB software, or any other application from the same computer, you may receive an error message informing you that the subsystem is reserved.

  • You must delete the object in the first session before you can use it in the next one.

Note   The Traditional NI-DAQ adaptor will be deprecated in a future version of the toolbox. If you create a Data Acquisition Toolbox™ object for Traditional NI-DAQ adaptor beginning in R2008b, you will receive a warning stating that this adaptor will be removed in a future release. See the supported hardware page at www.mathworks.com/products/daq/supportedio.html for more information.

Vendor Limitations

Measurement Computing Hardware