MATLAB import of DTS DataPro file format
This file will import Diversified Technical Systems Inc. (DTS) DataPro hybrid XML-ish/binary file format into a nested set of MATLAB dictionaries and structure. It does not try and interpret the file in any way. That is, it simply reads what is there and does basic error checking against the limited set of constraints that exist in the file format's documentation. As of this writing, the file format is poorly documented which makes it difficult to impossible to link the metadata that exists in the top-level .dts XML file to the information contained in the nested .CHN files. In any case, if you simply care about the ADC count data with basic information sufficient for a header, this reader will provide that.
To use, call importDTSFolder(folderpath) where folderpath is the path to a folder containing exactly one .dts file and the corresponding .chn files.
The return value is a structure with two fields, meta and contents. The meta field is a vector of meta structures and the contents field is a containers.Map where the key is the name of a .chn file and the value is a contents structure of the .chn file.
The meta structure contains three fields:
attributes- a containers.Map where the each key corresponds to the XML attribute name and its string valuevalue- DTS files do not contain uniform metadata, sometimes the value of a field appears as an XML attribute on a node, other times it is a value--that is, between opening <...> and </...> tags. If the XML node contains a non-attribute value, then it appears in this field. All leading and trailing whitespace is trimmed. If there are child nodes in this field in the original XML file, then the code throws an errorchildren- a containers.Map where the key corresponds to the name of the nested XML node and the value is anothermetastructure.
The contents structure describes version 4 of the .chn binary file. Currently it contains the following fields:
'versionNo',[], ...
'numSamples',[], ...
'bitsPerSample',[], ...
'samplesSigned',[], ...
'sampleRate',[], ...
'numTriggers',[], ...
'triggerSamples',[], ...
'pretestZeroLevelinCounts',[], ...
'removedADCLevelinCounts',[], ...
'pretestDiagnosticsLevelinCounts',[], ...
'pretestNoiseLevelinPercentageFS',[], ...
'posttestZeroLevelinCounts',[], ...
'posttestDiagnosticsLevelinCounts',[], ...
'dataZeroLevelinCounts',[], ...
'scaleFactormV',[], ...
'scaleFactorEU',[], ...
'EUFieldLength',[], ...
'engineeringUnits',[], ...
'excitation',[], ...
'triggerAdjustmentSamples',[], ...
'zeromVinCounts',[], ...
'windowAverageinCounts',[], ...
'originalOffsetinCounts',[], ...
'ISOCode',[], ...
'ADCCounts',[]);
ADCCounts is a vector of samplesSigned, bitsPerSample integers of the ADC counts. You multiply each count by the value of scaleFactorEU to get the actual engineering unit values.
##Limitations
The published documentation on the .chn file format claims that it uses a CRC32 checksum on the header data only. After discussing with DTS, they state that they actually use a crc16_CCITT where the other 2 bytes are zero but after trying many, many variations of this and other crc16 implementatons, I cannot reproduce their given checksum. A table-driven crc16_CCITT is included in the implementaton. In any case, a warning is printed that states that a checksum is not computed when reading each .chn file.
##Installing
You can simply put this file somewhere in your MATLAB folder path. Since many users are not too familiar with MATLAB packages, I chose to distribute this as a single file.
##Bugs and/or Enhancements
As stated, the DTS file/folder structure is not well documented. Any bugs that you come across, enhancements, or other insighes are greatly appreciated and will be incorporated.
##License
The contents of this repository are distributed under the BSD 3-clause license.