A lot of data in industrial sites is accompanied by interference and fluctuations, so most of the data needs to be filtered. Only after signal processing can we meet our control and use requirements. In this article, we introduce some technical issues in data precision processing, and other related filtering algorithms You can view the article in the signal processing column, and the related links are as follows:
First order RC low pass filter
One of the first-order low-pass (RC) filter algorithms in the PLC signal processing series_plc filter algorithm program_RXXW_Dor's Blog-CSDN Blog 1. Let's take a look at the advantages and disadvantages of RC filtering. Advantages: use digital filtering algorithms to achieve dynamic RC filtering, It can well overcome the shortcomings of analog filters; 1. This algorithm is more practical when the analog constants are required to be large; 2. It has a good suppression effect on periodic interference; 3. It saves RAM space Disadvantages: Insufficient The advantage is that it brings a phase lag, resulting in low sensitivity; at the same time, it cannot filter out interference with a frequency higher than half of the sampling frequency (called the Nyquist frequency) (for example, if the sampling frequency is 100Hz, it cannot filter out Except for interference signals above 50Hz) For interference signals higher than Nyquist frequency, _plc filtering algorithm program 
https://rxxw-control.blog.csdn.net/article/details/123755877Floating point precision processingcan be implemented using rounding instructions