The TDM Streaming (TDMS) file format has two versions: 1.0 and 2.0. Version 2.0 has all the capabilities of 1.0 plus additional capabilities.

Table 35. TDMS Version 1.0 and Version 2.0 Comparison
TDMS File Format Version Capabilities
1.0 Fundamental file operation features, including but not limited to:
  • Reading data from and writing data to a TDMS file
  • Getting and setting properties
2.0 All 1.0 capability plus the following:
  • You can write interleaved data to a TDMS file.
  • You can write TDMS data in different byte orders, or endian formats.
  • You can write TDMS data without using the operating system buffer. Doing so results in large performance improvements, especially in Redundant Array of Independent Disks (RAID) systems.
  • You can use NI-DAQmx to write raw data to TDMS files along with scaling information.
  • File format version 2.0 optimizes writing performance for contiguous data acquisition by using a single header for multiple chunks of contiguous data. This improves performance for single value acquisitions.
  • File format version 2.0 supports asynchronous writes to TDMS files. Asynchronous writes enable the application to process data in memory while writing data to a file instead of having to wait for the writing function to finish.

You can specify the version to create for a TDMS file with the TDMS Open function. You can convert a TDMS file between version 1.0 and 2.0 or vice versa with the TDMS Convert Format VI.