Crystal Instruments CI Data File Reader API

The CI Data File Reader consists of two Windows dynamic-linked libraries (DLLs) that give third-party applications an interface to Crystal Instruments measurement data. The data is stored in the ASAM Transport Format XML (ATFX) format, defined by the Association for Standardization of Automation and Measuring Systems (ASAM) Open Data Services (ODS) specification dedicated to storing vibration data and its various forms. CI software natively stores its data in ATFX for both signals and recordings, and users can easily view and export it.

An .atfx file is XML-based and stores signal data together with recording properties: recording time, length of recording, number of channels, channel parameters (such as input channel sensor and sensitivities), geographic coordinates, sampling rate and high-pass filter settings. It references a .dat file holding both raw time data and processed spectral data computed by Fourier transform, frequency response functions, cross-power spectrum, octave spectrum and more, plus two additional raw data files: a .ts timestamp file recording when a recording was saved with nanosecond accuracy, and a .gps file with the recording's latitude, longitude and altitude.

The API provides a streamlined reading and browsing library to decode ATFX, TS and GPS files. It supports Windows-based programs, ideally written in C#, and also supports Python, Matlab and LabVIEW. It offers direct calls to the ASAM ODS model classes used to store ATFX data, such as NVHMeasurement and NVHEnvironment for reading a DateTime with nanoseconds elapsed, and a Utility class that returns data without requiring knowledge of the underlying ODS model — for example GetListOfAllSignals and GetChannelTable. Users can read time or frequency signals in engineering units (for example acceleration m/s² converted to g, or EU_rms to EU_Peak) through the GetFrame function. Because display-related parameters such as spectrum type are not saved in the file, the default spectrum type is EU_rms², while engineering units are preserved.