Siemens SINAMICS S150 NEMA, Operating Instructions Manual

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Functions, monitoring and protective functions
9.3 Drive functions
Enclosed Drives
Operating Instructions, 12/2018, A5E36652151A
591
9.3.25.4 Freezing the actual speed for dn/dt errors
If, for high speed changes, the dn/dt monitoring function responds, then the "Freeze speed
actual value for dn/dt errors" function allows the speed actual value to be briefly "frozen"
therefore equalizing the speed change.
Commissioning
The "Freeze speed actual value for dn/dt errors" function is activated with p0437.6 = 1.
Sequence
The function runs as follows:
1.
If dn/dt monitoring responds (for p0492 > 0), then alarm A3x418 " Encoder x: Speed
difference per sampling rate exceeded"
1)
is output.
2. A frozen actual speed value limited to 2 current controller cycles is supplied.
3. The rotor position continues to integrate
4. The actual value is released again after 2 current controller cycles.
1)
x = encoder number (x = 1, 2 or 3)
9.3.25.5 Adjustable hardware filter
The adjustable hardware filter function allows an encoder signal to be filtered, therefore
suppressing short interference pulses.
Commissioning
The "adjustable hardware filter" is activated with p0438 > 0.
Parameterization
● A filter time in the range from 0 to 100 μ s can be entered in parameter p0438 (square
wave encoder, filter time). The hardware filter only supports values 0 (no filtering),
0.04 μ s, 0.64 μ s, 2.56 μ s, 10.24 μ s and 20.48 μ s
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.
● The effective filter time is displayed in parameter r0452.