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What does data frequency mean?

Erklärung des Begriffe "Datenfrequenz", "Abtastfrequenz", "Bandbreite" in den Datenblättern von Messverstärkern

Data frequency: Number of measured values ​​per second transmitted via the interface. The data frequency is usually adjustable in the configuration software of the measuring amplifier.

Sampling frequency: Number of analog / digiatations per second. Often also specified as a "summary sampling frequency or sum sampling rate for all channels of the measuring amplifier in the data sheets.

Bandwidth: occasionally used in data sheets of measuring transgrets as a synonym for data frequency, data transfer rate, data rate

Measuring amplifiers with interface convert the analog signal into a digital signal with the help of an analog/digital converter. This happens at fixed (often configurable) intervals. The analog/digital converter captures the analog signal of the so-called sampling frequency. Similar to analog filters, the scattering of the signals is reduced. This is done by using digital filters.

The simplest digital filter is the averaging filter. The use of a digital filter (usually) reduces the amount of data. The data made available via the interface (USB, RS232, UART, CANbus, Ethernet, etc...) are sent at fixed intervals with the data frequency. 

A very low data frequency often has a negative effect on a control loop. Therefore, the moving average is usually used. With the moving average, the number of data at the output remains equal to the number of data at the input of the filter. High frequencies are filtered, which can be most clearly seen with the so-called step response of the filter: A signal jump at the input is reproduced with a transient response time at the output.

The time constant of a mean value filter is the number of averages "m". times sampling interval "T" (with very good approximation from 100 averages). The cut-off frequency Fg of a filter is related to the time constant: Fg = 1/(2 pi m T). 

At an internal sampling frequency of e.g. 10.000Hz and a configured data frequency of e.g. 100Hz, the cut-off frequency is about 16Hz. Rule of thumb: The cut-off frequency is about 1/6 of the (set) data frequency.

https://www.me-systeme.de/en/technology-first/electronics/basics/filter

https://www.me-systeme.de/en/technology-first/electronics/basics/comparison

https://www.me-systeme.de/en/technology-first/electronics/gsv-6/aufloesung-gsv-6bt