You can specify the amount of samples written per TDMS file using the DAQmx Read property
Logging:Samples Per File. This property specifies how many samples to write to each file. When the file reaches the number of samples specified, a new file is created with the naming convention of <filename>_####.tdms, where #### starts at 0001 and increments automatically with each new file.
To programmatically set this property, follow these instructions:
- Drop a DAQmx Read Property Node onto the block diagram.
- After clicking on the property node, select Samples Per File under the Logging category.
- Wire the DAQmx Read Property Node to your DAQmx Read function to set the property and specify a number of samples to write per file.