With MXI-3 or MXI-4 and Analog Output, I Get Bandwidth Limitation Errors at High Update Rates. Hardware: VXI/VME/MXI>>MXI Interfaces>>PCI-MXI-2
Problem: I am using an analog output board through the MXI-3 or MXI-4 interface. When I use a high update rate, I get bandwidth errors such as: Warning -10843 occurred at an unidentified location. Possible reasons: NI-DAQ LV: Because of system and/or bus-bandwidth limitations, the driver could not write data to the device fast enough to keep up with the device throughput; the onboard device memory reported an underflow error. How can I achieve high update rates? Solution: If you are using analog output through MXI-3 or MXI-4, you will probably get better performance results by enabling interrupt driven transfers instead of DMA driven transfers. You can do this in LabVIEW with the Set DAQ Device Info VI. Use the following settings: MXI-3 and MXI-4 are transparent interfaces for PCI, but through testing we have found that interrupt driven transfers are more efficient for analog output. There are other potential solutions to consider as well. One is to use the Onboard FIFO Mode Analog Output. In this mode, you can output a limited amount of data with no bandwidth restrictions by fitting your data into the onboard FIFO. Please refer to KnowledgeBase 2OI95OEW: What is FIFO Mode Analog Output and How Do I Use It? in the related links section for more information. Another idea to consider is the use of an Arbitrary Waveform Generator (ARB). For some applications, the ARB can be more flexible and give higher performance than the standard data acquisition output boards. Please refer to Developer Zone Tutorial: Arbitrary Waveform Generators in the related links section for more information. Related Links: KnowledgeBase 2OI95OEW: What is FIFO Mode Analog Output and How Do I Use It? Developer Zone Tutorial: Arbitrary Waveform Generators Product Specifications: MXI-3 Specification Sheet Product Specifications: MXI-4 Specification Sheet Product Manuals: MXI-4 Series User Manual and Specifications Attachments:
Report Date: 09/09/2002 Last Updated: 02/15/2008 Document ID: 2P8BP7UJ |
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