Added descriptions of the ANALOG:FORMAT and ANALOG:BITS parameters that required to enable software applications to read C3D files that contain unsigned 16-bit integer data. These can be found at the end of the chapter discussing the required analog parameters. These descriptions, and an additional discussion at the start of the chapter, should be read carefully by anyone attempting to read or write 16-bit analog data values in C3D files. This is mandatory reading for anyone maintaining 3rd party applications that read analog C3D data.
The possibility of encountering unsigned 16-bit integers within the analog data storage has lead to substantial alteration of the descriptions of most of the parameters controlling analog data. In particular, the chapter describing the ANALOG:OFFSET parameter has had to be completely rewritten to accommodate the possibility of interpreting the parameter as either a signed or unsigned integer value depending on the format used to store analog data values. A brief chapter has been added at the end of the ANALOG:OFFSET discussion that describes methods of “zeroing” analog data to remove measurement offsets. While this document takes no position as to the merits of any of the data zeroing methods described, users are strongly encouraged to use signed integers when storing analog data values where ever possible.
The description of the ORIGIN(3) parameter for TYPE-3 force plates has been changed to make it clear that this value is normally negative.
Various typographic errors have been either fixed (or moved to new areas of the document). Please let us know if (when) you find any errors or vague descriptions that could be improved. Please feel free to write additional descriptions or items for inclusion in this document and submit them to the C3D-L list.
To keep the bankers, lawyers and other folk happy, a formal redistribution clause setting out the terms and conditions for the redistribution of this document by third parties has been added to the manual. This simply sets out the previous “freely available to all” policy in more formal terms.