Digital Interface Dynamic Error when Inputting Analog Sensor Signals in Control and Monitor Systems

摘要

In the article, using the well-known provisions of the sampling theorem and Bernstein inequality, the maximum dynamic error of the digital interface is estimated when analog sensor signals are input in standard control and monitor systems (CMS). It is shown that for the case when the input module polls the sensor primary transducer (PT) having a finite spectrum with an extremely low frequency determined by the sampling theorem, the dynamic error is 157%. To reduce this error to acceptable values, it is necessary either to increase the sampling frequency (i.e., the rpm of the interface bus with the exchange protocol) by a factor of hundreds and thousands of times compared to the sampling frequency calculated by the sampling theorem, or reduce the operating speed of the CMS by a factor of hundreds and thousands of times.