The TDM data model offers three levels of hierarchy, as shown in Figure 1 – file, group, and channel. The file level can contain an unlimited number of groups, and each group can contain and unlimited number of channels. Because of this channel grouping, you can organize your data to make it easier to understand. For example, you may have one group for your raw data and another group for your analyzed data within one file. Or, you may have multiple groups that correspond to sensor types or locations.
Figure 1. Each TDMS file written in LabVIEW contains descriptive information on the root, group, and channel levels.
Also, you can insert your own custom properties at each of the three levels. Each level accepts an unlimited number of custom-defined attributes to achieve well-documented and search-ready data files. The descriptive information located in the TDM or TDMS file, a key benefit of this model, provides an easy way to document the data without having to design your own header structure. As your documentation requirements increase, you do not have to redesign your application; you simply extend the model to meet your specific needs.