DAQmx Buffer Size Allocation for Finite or Continuous Acquisition

Updated Nov 6, 2023

Reported In

Driver

  • NI-DAQmx

Issue Details

  • How does DAQmx allocate buffers?
  • How large is my acquisition buffer?
  • How do I make my buffer size larger?
  • Why am I getting a buffer overflow error?

Solution

With NI-DAQmx, memory allocation is typically handled automatically for you in the DAQmx Timing function:
  • If the acquisition is finite (sample mode on DAQmx Timing function is set to Finite Samples), NI-DAQmx allocates a buffer equal in size to the value of samples per channel
  • If the acquisition is continuous (sample mode on the DAQmx Timing function is set to Continuous Samples),  NI-DAQmx will allocate a buffer according to the following table:
 
 
Sample RateBuffer Size
0-100 S/s1 kS
100-10,000 S/s10 kS
10,000-1,000,000 S/s100 kS
>1,000,000 S/s1 MS
 
 

Additional Information

This information can all be found in the NI-DAQmx Help documentation. In Windows, you can find this documentation by going to Start»Programs»National Instruments»NI-DAQ. In the help file, this specific information is located in the Buffering section under Key NI-DAQmx Concepts. Along with this topic, many other common questions and problems can be answered through the information in this help file.

Related Links

 

Other Support Options

Ask the NI Community

Collaborate with other users in our discussion forums



Request Support from an Engineer

A valid service agreement may be required, and support options vary by country.