As soon as a limit value is exceeded, the corresponding alarms can be read out in Index
4575 to 4577.
Automatic teach-in of the limits
The teach-in process can be started via Index 4581 and makes it possible to automati‐
cally set the limit values described in
. The teach-in is controlled by the same
settings as for the reduced analysis, but in addition the number of teach-in cycles is
relevant for the standard analysis.
Frequency tolerance (Index 4580, Subindex 1):
Tolerance in the frequency range. A value of 20, for example, sets the limits so that
values of 380 to 420 Hz are permitted at a frequency of 400 Hz. If the value exceeds or
falls below the limit, the associated alarms are triggered.
Tolerance factor for the amplitude (Index 4580, Subindex 2):
Tolerance in amplitude. The upper amplitude limit (maximum) is calculated by multiply‐
ing the current measured value by this factor. The lower amplitude limit (minimum)
is calculated by dividing the current measured value by this factor. A factor of, for
example, 2 thus sets the upper limit to 1 g and the lower limit to 0.5 g for an amplitude
of 0.25 g.
Example of a peak to be monitored:
•
Frequency: 400 Hz
•
Amplitude: 0.5 g
Selected tolerances:
•
Frequency: 20 Hz
•
Amplitude factor 2
Resulting limits:
•
Frequency: Minimum 380 Hz, maximum 420 Hz
•
Amplitude: Minimum 0.25 g, maximum 1 g
Number of teach-in cycles (Index 4580, Subindex 3):
The number of teach-in cycles indicates how many individual spectra are analyzed by
the teach algorithm to derive the limits. A larger number of teach-in cycles allows the
fluctuations of the values in the spectrum to be better reflected in the automatically
generated tolerance limits, but at the same time, a larger number of teach-in cycles
also extends the duration of the teach-in process. The approximate duration of the
teach-in process can be estimated as follows:
Teach-in duration = 2 x block length in seconds x number of blocks for averaging x
number of teach-in cycles
The progress of the teach-in process can be monitored via Index 4582. It is completed
when the value 100 is output at this point. The taught frequency ranges and amplitude
limits then appear in Index 4566-4572.
Frequency ranges and amplitude limits that have already been set manually or the
values from an earlier teach-in process are overwritten in the process. The manually or
automatically set frequency ranges and amplitude limits can be reset to their default
values by writing the value 1 in Index 4573.
9.3.3
Readout of raw data
In addition to the reduced vibration information (indication values in the time range and
detected peak frequencies and peak amplitudes in the frequency range), it is possible
with the Multi Physics Box to read out both the raw acceleration data in the time range
and the entire vibration spectrum.
9
OPERATION
40
O P E R A T I N G I N S T R U C T I O N S | MPB10
8028041/2022-08-16 | SICK
Subject to change without notice
