Tolerance Band Pulse Number" Monitoring - Siemens SINAMICS S120 Function Manual

Basic functions
7.20 Tolerant encoder monitoring
7.20.8

"Tolerance band pulse number" monitoring

This function monitors the number of encoder pulses between two zero marks. An alarm is
output if the number lies outside a tolerance band that can be selected.
Commissioning
1. Set parameter p0437.2 = 1 to activate the monitoring.
2. Using parameters p4683 and p4684, set the upper and the lower limits of the tolerance
band. Within this tolerance band, the detected number of pulses is considered to be
correct.
Sequence
1. After each zero mark, it is again checked as to whether up to the next zero mark the
number of pulses lies within the tolerance band. If this is not the case and "pulse number
correction for faults" (p0437.2 = 1) is parameterized, then alarm A3x422
seconds.
2. If one of the limits has a value of 0, then alarm A3x422
3. Display of uncorrected encoder pulses
For p0437.7 = 1, the number of corrected pulse errors is displayed in r4688 with the
correct sign. Set p0437.7 = 0 in order to indicate the corrected pulse errors per zero mark
distance in r4688.
For a drift after one revolution, if the tolerance band limit is not reached, an alarm is not
output. A new measurement is performed if the zero mark is exceeded.
4. Number of pulses outside the tolerance band
If the tolerance band is violated, then in addition to alarm A3x422
This value remains for a minimum of 100 ms, so that a controller can detect several
violations in quick succession one after the other even for high-speed drives.
You can send the message bits of parameter r4689 to a higher-level controller via
PROFIBUS / PROFINET as process data.
5. You can send the accumulated correction value to a higher-level controller via
PROFIBUS (e.g. p2051[x] = r4688). The controller can then set the contents of the
counter to a specific value.
Note
The "tolerance band pulse number monitoring" also functions for external encoders which
operate in a drive line-up as leading value encoder (monitoring the position value XIST1
from a direct measuring system).
x = encoder number (x = 1, 2 or 3)
1)
378
1)
is deactivated.
1)
r4689.1 = 1 is set.
1)
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
is output for 5
Drive functions