Input Buffer Size Stuck at 1000 Samples when Running DAQmx Text-Based Acquisition

Updated Aug 19, 2026

Reported In

Driver

  • NI-DAQ™mx

Programming Language

  • C
  • Python
  • C++

Issue Details

I'm configuring a DAQmx continuous acquisition in a text-based language like C or Python, and am unable to read more than 1000 samples with my acquisition. How do I need to modify the DAQmxCfgSampClkTiming() method to correct this behavior?

Solution

This behavior is the result of not defining the sampsPerChanToAcquire parameter when calling DAQmxCfgSampClkTiming() in your program. This value needs to be specified for both continuous and finite acquisitions, and if it is not specified, the value defaults to 1000, leading to the behavior being observed. Specifying this value will allow you to collect more samples in your acquisition, and have greater control over the number of samples acquired by your program.

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