Import/Export of TDM Files

The addin converts TDM and TDMS files to UniPlot-netCDF data files and netCDF files to TDM files.

TDM files are created by DIAdem or Labview (National Instruments). The addin is based on the DIAdem Connectivity Library nilibddc.dll of National Instruments.



TDM Import

  • Choose File=>Import Data.
  • Choose Type “TDM File (*.tdm; *.tdms)”.
  • Select one or more TDM files.

TDM Export

  • Open an NC file using the File=>Import Data command.
  • click on the “>>” button.
  • Right click in the data grid and choose Export=>Save AS TDM File.
  • Choose a name for the TDM file.


Use the Tools=>TDM Import Configuration to set the option for creating the channel names in the NC file.


In TDM format, channels are organized in groups. In netCDF files the group is replaced by a group number, for example: G1_ZWSTAT. The group number is only used for TDM files containing more than one group.

The following parameters are read from the Windows-Registry:

Key Type Default Value Description
"Settings\TDM_StripGroupName" Number 0 Flag for TDM import. If the flag is set to 1, the channel name in the netCDF files does not contain the group name, e.g. G1_.
WriteProfileInt("Settings", "TDM_StripDeviceName", 1)

See also UniPlot’s Use of the Windows Registry.

Programming Interface

The programming interface is similar to the interface documented by National Instruments. The following table contains all supported functions. An example can be found in the uniplot\addin\rs_tdm\rs_tdm.ic file.

Original-Function UniScript-Function
DDC_CreateFile _DDC_CreateFile
DDC_AddChannelGroup _DDC_AddChannelGroup
DDC_AddChannel _DDC_AddChannel
DDC_SaveFile _DDC_SaveFile
DDC_CloseFile _DDC_CloseFile
DDC_OpenFileEx _DDC_OpenFileEx
DDC_RemoveChannelGroup _DDC_RemoveChannelGroup
DDC_RemoveChannel _DDC_RemoveChannel
DDC_CloseChannelGroup _DDC_CloseChannelGroup
DDC_CloseChannel _DDC_CloseChannel
DDC_OpenFile Verwenden Sie _DDC_OpenFileEx
DDC_SetDataValues _DDC_SetDataValues
DDC_AppendDataValues _DDC_AppendDataValues
DDC_ReplaceDataValues _DDC_ReplaceDataValues
DDC_GetNumChannelGroups -
DDC_GetChannelGroups _DDC_GetChannelGroups
DDC_GetNumChannels -
DDC_GetChannels _DDC_GetChannels
DDC_GetNumDataValues _DDC_GetNumDataValues
DDC_GetDataValues _DDC_GetDataValues
DDC_GetDataType _DDC_GetDataType
DDC_SetFileProperty _DDC_SetProperty
DDC_GetFileProperty _DDC_GetProperty
DDC_GetFileStringPropertyLength Not necessary.
DDC_CreateFileProperty _DDC_CreateProperty
DDC_FilePropertyExists _DDC_PropertyExists
DDC_GetNumFileProperties -
DDC_GetFilePropertyNames _DDC_GetPropertyNames
DDC_GetFilePropertyType _DDC_GetPropertyType
DDC_SetChannelGroupProperty _DDC_SetProperty
DDC_GetChannelGroupProperty _DDC_GetProperty
DDC_GetChannelGroupStringPropertyLength Not necessary.
DDC_CreateChannelGroupProperty _DDC_CreateProperty
DDC_ChannelGroupPropertyExists _DDC_PropertyExists
DDC_GetNumChannelGroupProperties -
DDC_GetChannelGroupPropertyNames _DDC_GetPropertyNames
DDC_GetChannelGroupPropertyType _DDC_GetPropertyType
DDC_SetChannelProperty _DDC_SetProperty
DDC_GetChannelProperty _DDC_GetProperty
DDC_GetChannelStringPropertyLength Not necessary.
DDC_CreateChannelProperty _DDC_CreateProperty
DDC_ChannelPropertyExists _DDC_PropertyExists
DDC_GetNumChannelProperties -
DDC_GetChannelPropertyNames _DDC_GetPropertyNames
DDC_GetChannelPropertyType _DDC_GetPropertyType
DDC_GetLibraryErrorDescription Not necessary.
DDC_FreeMemory Not necessary.

Licensing Conditions

Portions used under license from National Instruments Corporation; copyright (c) 2007 National Instruments Corporation.

The complete license text can be found in EmbeddedUSICopyrights.chm and license.rtf in the addin/rs_tdm directory.


Version Description
R2023.0 Source library update - National Instruments TDM DLL (V17)
R2012.11 Group name can be added to channel name.
R2012.9 New DLLs with TDM Streaming (.tdms) 2.0 file format support added.
5.5.0 New.