Measurement Filtering

Introduction

The type of filtering performed by the system is called "first order filtering." The filtering coefficient is editable through the Control Expert screen or through a program.

Mathematical Formula

The applicable mathematical formula is as follows:

where:

α = filter efficiency,

Mesf(n) = filtered measurement at time n,

Mesf(n-1) = filtered measurement at time n-1,

Valb(n) = raw value at time n.

The user configures the filtering value from among 7 possibilities. This value may be changed even when the application is in RUN mode.

NOTE: Filtering is disabled in Fast Cycle mode.

Values for the TSX AEY 414 Module

Filtering values are as follows:

Desired Efficiency	Required Value	α corresponding	Filter Response Time at 63%	Cut-off Frequency (in Hz)
No filtering	0	0	0	0
Low filtering	1 2	0.750 0.875	1.91 s 4.12 s	0.083 0.039
Medium filtering	3 4	0.937 0.969	8.45 s 17.5 s	0.019 0.0091
High filtering	5 6	0.984 0.992	34.1 s 68.5 s	0.0046 0.0022