Manually setting the limits
For monitoring, the limit values for the frequency and amplitude of the respective peaks
can be set in Index 4565.
Automatic teach-in of the limits
The teach-in process can be performed separately for
Dominant peak
and
Fundamental
peak
via Index 4581. The tolerances defined in Index 4580 are placed around the
measured values.
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. When exceeded, 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 0.5 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
If the frequency or amplitude of the peaks change beyond the set limits, corresponding
alarms are output. The
Dominant peak
and
Fundamental peak
are monitored independently
of each other, and the limit values must be set separately for each. The areas between
the peaks and also the remaining detected peaks are not monitored in the reduced
analysis. The standard analysis must be used for this purpose.
9.3.2.2
Standard analysis (Index 4555-4582)
In the standard analysis, the sensor outputs up to 16 frequency and associated ampli‐
tude values. Only the 16 peaks with the highest amplitude are output. As shown in
, these are output starting with the lowest frequency in ascending order up to
the highest frequency via Index 4555 together with the amplitude. A newly appearing
peak is sorted according to its frequency and can thus displace peaks with smaller
amplitudes from visibility. The
Dominant peak
and
Fundamental peak
always appear in the
16 output peaks, with the
Fundamental peak
always representing peak 1.
OPERATION
9
8028041/2022-08-16 | SICK
O P E R A T I N G I N S T R U C T I O N S | MPB10
37
Subject to change without notice
