Adjustable Hardware Filter - Siemens SINAMICS S120 Function Manual

7.19.4

Adjustable hardware filter

The adjustable hardware filter function allows an encoder signal to be filtered, therefore
suppressing short interference pulses.
Commissioning
1. Set parameter p0438 ≠ 0 to activate the "adjustable hardware filter" function.
Parameterization
1. In parameter p0438 (square-wave encoder filter time) enter the filter time in the range
2. You can see the active, effective filter time in parameter r0452.
Effect
You can calculate the influence of the filter time on the maximum possible speed as follows:
n_max [rpm] = 60 / (p0408 · 2 · r0452)
Here, p0408 is the pulse number of the rotary encoder.
Example
Specifications:
● p0408 = 2048
● r0452 = 10.24 [μs]
n_max is then calculated as follows:
● n_max = 60 / (2048 · 2 · 10.24 · 10
As a consequence, with this filter time you can operate the motor up to a maximum of 1430
rpm.
x = encoder number (x = 1, 2 or 3)
1)
Drive functions
Function Manual, (FH1), 04/2014, 6SL3097-4AB00-0BP4
from 0 to 100 μs. The hardware filter only supports values 0 (no filtering), 0.04 μs,
0.64 μs, 2.56 μs, 10.24 μs and 20.48 μs
If a value is set that does not match one of the discrete values specified above, the
firmware automatically sets the next closest discrete value. The drive does not output an
alarm or fault message.
Note
The zero mark alarms F3x100, F3x101 and F3x131
mark with a width of ¼ encoder pulse at half n_max speed, are suppressed when the
hardware filter is activated.
7.19 Tolerant encoder monitoring
, that are already output for a zero
1)
) = 1430 [rpm]
-6
Basic functions
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