Hi bull balls,
Actually, I had first attempted the same approach as Stefan but made 2 errors in my test code and incorrectly concluded that the DataFileHeaderAccess() object was not able to edit a TDMS file. I fixed those errors and verified today that in DIAdem 11 you CAN edit the values of TDMS properties (File/Group/Channel) and even create brand new properties in the TDMS file, without loading the file, using this object. So that would be my recommendation for the easiest way to edit the TDMS property set from a DIAdem VBScript. Note that if you have the TDMS file register-loaded in the Data Portal that the DataFileHeaderAccess() object can not edit the TDMS properties. In this case you need to then re-index the TDMS file for the updated properties to show up in the DataFinder.
If, on the other hand, you are actually interested in programmatically editing the property values of the TDMS file, without loading it, using LabVIEW-- with no interaction with DIAdem or the Data Portal, then you can use the attached VI as an example of how this would work. In this case you need to delete the existing TDMS_Index file and re-index the data file for the property changes to show up in the DataFinder. The TDMS file can not be register-loaded in DIAdem when you delete the TDMS_Index file.
Brad TurpinDIAdem Product Support EngineerNational Instruments
Append TDMS Property.vi:
http://forums.ni.com/attachments/ni/60/9183/1/Append TDMS Property.vi