Pulse Number Correction For Faults - Siemens SINAMICS S120 Function Manual

Basic functions
8.21 Tolerant encoder monitoring
Commissioning the function
Set p0430.22 = 1 to activate the function.
8.21.7

Pulse number correction for faults

Overview
Interference currents or other EMC faults can falsify encoder evaluation. However, it is possible
to correct the measured signals using the zero marks.
Commissioning the function
Carry out the following steps to start the function:
1. Set p0437.2 = 1 to activate "Pulse number correction for faults".
2. Define the permissible tolerance (encoder pulses) for the zero mark distance (p4680).
3. Define the limits of the tolerance window, up to which the drive corrects the pulse number
(p4681, p4682).
4. Using p4686, define the minimum zero mark length.
Further information on the procedure
The function extension completely corrects encoder pulse errors up to the tolerance window
(p4681, p4682) between two zero marks. The rate of correction is ¼ encoder pulses per current
controller cycle. As a consequence, it is possible to continually compensate for missing
encoder pulses (for example, if the encoder disk is dirty). Using the parameters p4681 and
p4682, set the tolerance for the deviating pulse number. If the deviation exceeds the tolerance
window size, fault F3x131
Note
When the "Commutation with zero mark" function (p0404.15 = 1) is activated, then the system
waits until fine synchronization has been completed before making a correction (r1992.8 = 1).
The pole position for the commutation is also corrected. To do this, you do not have to activate
pole position adaptation (p0430.22 = 1). This function does not make any corrections in
rotational speed acquisition.
Using p4686, set the minimum zero mark length. With a factory setting of 1, it is prevented that
EMC faults result in a zero mark error. Shorter zero marks are only suppressed when "Zero
mark edge detection" is parameterized (p0437.1 = 1).
Zero mark deviations of less than the minimum zero mark length (p4686) are not corrected.
A permanently failed zero mark is indicated using the fault F3x101 "Encoder x: Zero mark
failed"
x = encoder number (x = 1, 2 or 3)
1)
374
is output.
1)
or the alarm A3x401
1) 1)
"Alarm threshold zero mark failed".
Function Manual, 06/2019, 6SL3097-5AB00-0BP2
Drive functions