Siemens SINAMICS S120 Function Manual page 549

● Bit status 0: Default
● Bit status 1: Operating mode
Zero mark monitoring
Zero mark monitoring is activated with parameter setting p0437.2 = 1.
p4680[0...n] Zero mark monitoring permissible tolerance
Sets the permissible tolerance in encoder pulses for zero mark monitoring. Permissible
tolerance until the zero mark is reached again.
Range: 0 ...1000, default: 1
Minimum length of zero mark
The following parameter setting can be used to check the minimum length of the zero mark:
p4686 Minimum length setting of zero mark
● Setting range: 0 to 2
Fault monitoring zero mark detection
Encoder faults are monitored as before by means of fault
F3x101 encoder x: zero mark failure
or alarm
A3x401 encoder x: alarm threshold zero mark failure
(x = encoder number 1-3).
Pulse number correction for rectangular signal encoders
The correction function is activated with p0437.2.
● Bit status 0: Function disabled (default).
● Bit status 1: Function active
X_IST1 supplies pulses which may be set to the nominal number of pulses by the correction
function when the next zero mark is detected.
The pulses are also corrected at the rotor position for commutation.
The speed sensing function is not corrected. Corrections are made directly in the SMC.
With the parameters
p4681[0...n] Tolerance window zero mark positive limit
default: 2 (equals 2 encoder pulses), max. 1000
and
p4682[0...n] Tolerance window zero mark negative limit
default: -1001, max. -1001: negated value of p4681
, it is possible to set the tolerance for deviations in pulse number. When the deviation
exceeds the tolerance window, encoder fault F3x131 is signaled (x = encoder number 1-3).
Note
The "positive limit" defines additional pulses counted as a result of EMC interference. The
"negative limit" defines the number of pulses lost in the encoder as a result of dirt on the
encoder glass disk.
Drive functions
Function Manual, (FH1), 10/2008, 6SL3097-2AB00-0BP5
Pure edge zero mark detection.
, but less than the zero mark distance in p0425. The drive does not
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allow the length limit specified in p0425 to be exceeded and outputs the message "Value
higher than p0425" in STARTER if the length input is too high.
11.5 Tolerant encoder monitoring with SMC30
Applications
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