Analog Data Sample
Analog data stored in a C3D normally consists of a number of analog measurements that have all been recorded at a single instant of time from each analog channel that is being sampled. All analog data samples are recorded in sequence at regular intervals defined by the parameter ANALOG:RATE, which is written as a frequency value in Hertz. It is required that every analog data sample must contain the same number of analog measurements defined by the parameter ANALOG:USED.
Additional critical factors in recording accurate analog samples are the ADC input range settings, the analog sample rate, and the scaling calculations that convert each data sample into real-world values. Both the individual ADC input range settings and the ADC sample rate are controlled by the data collection system and any changes that affect the sampled signal must be recorded in the appropriate C3D analog parameters so that the analog data can be accurately reconstructed.