Filter operation
Velocity filter (Index 0x8000:18)
The EL5001-0090 Terminal (from FW02, Rev.0017) is equipped with a digital filter that can assume the characteristics of an Infinite Impulse Response filter (IIR filter).
The filter is disabled by default (value: "0" (None)).
IIR filter
The filter with IIR characteristics is a discrete time, linear, time invariant filter that can be set to eight levels (level 1 = weak recursive filter, up to level 8 = strong recursive filter).
The IIR can be understood as a sliding average value calculation after a low-pass filter.
Here, the IIR filters work cycle-synchronously and are thus updated depending on the cycle time.
 | IIR filter Difference equation: Yn = Xn * a0 + Yn-1 * b1 |
Velocity | Value | PDO update time | Filter property | Comment | Rise time |
|---|---|---|---|---|---|
0 | None | - | - | Filter disabled | - |
1 | IIR 1 | Cycle-synchronous | Low-pass filter | a0 = 1/21 = 0.5 | 3 |
2 | IIR 2 | a0 = 1/22 = 0.25 | 8 | ||
3 | IIR 3 | a0 = 1/23 = 0.125 | 17 | ||
4 | IIR 4 | a0 = 1/24 = 0.0625 | 34 | ||
5 | IIR 5 | a0 = 1/25 = 0.03125 | 69 | ||
6 | IIR 6 | a0 = 1/26 = 0.015625 | 140 | ||
7 | IIR 7 | a0 = 1/27 = 0.0078125 | 280 | ||
8 | IIR 8 | a0 = 1/28 = 0.00390625 | 562 |
