Siemens SIMATIC 505 - Filter on Position

Selected Functions
5-9
5.3.2
A filter on position* is provided for cases where low levels of harmonics are
present. While this filter has its constants specifically chosen for 60 Hz
harmonic rejection, it does work with many other harmonics as well.
The formula for this first order filter and an example with values follows:
new input  filter constant (read input  previous input)  previous input
      
   
     
A smaller filter constant gives more damping of input and more effective
filtering. The example below illustrates the effect of a smaller filter
constant on new input value.
      
   
   
*See Constant 14, bits 4–7 on page 2-19.
Filter on Position