Archived: USB NI 63xx X Series Bugs Fixed in NI-DAQmx 9.3

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NI has recommended that all USB X Series customers upgrade to DAQmx 9.3 if they are using an earlier version of the driver. This document lists the specific bugs that were fixed in DAQmx 9.3 that prompted this recommendation.

NI-DAQmx 9.3 contains bug fixes for the following issues present on X Series devices (NI USB-63xx) when used with earlier versions of the driver.  If you believe any of these issues have the possibility of affecting your application, NI recommends that you upgrade to NI-DAQmx 9.3.

Digital I/O Glitches on Computer Restart

In NI-DAQmx 9.2.3 and earlier, if a USB X Series device remains powered during a computer restart, the digital lines will glitch high for approximately 1-2 seconds before loading programmable power-up states.  This behavior only occurs on lines that were previously being driven low at the time of the the computer restart.  If a line was being driven high or configured as an input (i.e. tri-state) at the time of the restart, then the glitch would not occur.

Starting with NI-DAQmx 9.3, the digital lines retain their original value until the programmable power-up states are loaded.

Digital I/O Returns/Generates 0 in Some Cases:

In DAQmx 9.2.3 and earlier, USB X Series devices with 32 digital I/O lines on port 0 (NI USB-6343, NI USB-6353, and NI USB-6363) may return or generate 0  lines if either of the following cases are met:

  • A Digital Input or Output task contains 8 or fewer lines and does not include any of lines 0:7
  • A Digital Input or Output task contains 16 or fewer lines and does not include any of lines 0:15

The behavior may be worked around by including the lines mentioned above, but has been corrected for in NI-DAQmx 9.3.

Analog Input Channels Swap in Some Cases (Multiplexed Boards Only)

In DAQmx 9.2.3 and earlier, multiplexed USB X Series devices may return data from the incorrect channels if the following events occur sequentially:

  1. A multi-channel analog input task is explicitly committed.  An example use-case of 
    committing a task can be found here.
  2. The task is started.
  3. The task is stopped before it has finished its acquisition.
  4. The task is restarted.

If the device is in the middle of converting samples when it is stopped (step 3 above), then upon restart DAQmx will return data from the incorrect channels.

Encountering this issue should be very rare given that there are not any obvious use-cases for performing the above steps as described.  The behavior is corrected in NI-DAQmx 9.3.

Related Links: 
Driver Download Page: NI-DAQmx 9.3

Glossary of Terms


  • Bug ID - When an issue is reported to NI, you may be given this ID or find it on  You may also find IDs posted by NI on the discussion forums or in KnowledgeBase articles.
  • Legacy ID – An older issue ID that refers to the same issue.  You may instead find this issue ID in older known issues documents.
  • Description - A few sentences which describe the problem. The brief description given does not necessarily describe the problem in full detail.
  • Workaround - Possible ways to work around the problem.
  • Reported Version - The earliest version in which the issue was reported.
  • Resolved Version - Version in which the issue was resolved or was no longer applicable. "N/A" indicates that the issue has not been resolved.
  • Date Added - The date the issue was added to the document (not the reported date).