Estimation to Efficiency of the Using of Anti-Alias Filter in the A/D Interface of Instrumentation and Control Systems

The analysis of dynamic errors of input circuits of A/D interface (ADI) of the instrumentation and control systems is carried out. It is shown that the main influence on the magnitudes of these errors is due to the effect of aliasing during sampling of the sensor signal in the analog multiplexer (AM) and data delay in the analog anti-aliasing filter (AAAF). The use of the Filter Solution application software and the NI LabVIEW software environment enabled us to obtain numerical evaluations of the dynamic errors: aliasing errors and errors caused by signal delay in the AAAF. The article shows that it is problematic to use the AAAFs in instrumentation systems due to the sensor signal delay.