5.
This allows a 224 byte array containing 112 raw data values to be read in Index
4588. The data format of the individual values is a 16 bit wide signed integer –
int16.
6.
After that the segment number (Index 4587, Subindex 1) can be increased and
then the next segment can be accessed. To reduce the number of write operations
and thus the readout time, the segment number is automatically incremented
after each read of Index 4588. It is thus sufficient to cyclically read out the data
from Index 4588 to obtain the raw time range data of an axis.
By reading out the data segment by segment, a vector of single raw values is obtained
whose length is a multiple of 112. This must be trimmed to the length of the valid data
points (Index 4586, Subindex 2) at the end.
To scale the raw values to [g], the raw data values must be multiplied by the factor
244/1e6.
To read out the raw values of other axes, the corresponding axis is selected in Index
4587, Subindex 2 and the segment selection is set back to 0 in Subindex 1. The data
can then be read out via Index 4588 as described.
9.3.3.2
Readout of the entire frequency spectrum (Index 4585-4590)
The complete frequency spectrum can be used to identify whether other frequencies
may be of interest in addition to the 16 peaks displayed, or whether certain ranges can
be ignored.
NOTE
The vibration frequency spectrum is only available in a single axis. The desired axis is
selected in the settings of the vibration analysis – Index 4477. This setting must take
place before activating
Snapshot
mode.
The frequency spectrum can be read out via the following procedure:
1.
Activate
Snapshot
mode via Index 4585 = 2. This can be used to request the
frequency spectrum.
2.
Wait until the availability of the data is indicated by a 2 in Index 4586, Subindex 2.
Now the readout can be started.
3.
Select the first segment by writing a 0 in Index 4589, Subindex 1.
4.
This allows a 224 byte array containing 56 frequency spectrum values to be read
in Index 4590. The data format of the individual values is a single measurement
accuracy floating point number – float32.
5.
After that the segment number (Index 4589, Subindex 1) can be increased and
then the next segment can be accessed. To reduce the number of write operations
and thus the readout time, the segment number is automatically incremented
after each read of Index 4590. It is therefore sufficient to cyclically read out the
data from Index 4590 to obtain the frequency spectrum.
By reading out the data segment by segment, a vector of raw spectrum values is
obtained whose length is a multiple of 56. This must be trimmed to the length of the
valid data points (Index 4586, Subindex 2) at the end.
The raw spectrum values read out are the amplitudes at fixed frequencies. The first
value indicates the amplitude at 0 Hz, the following frequency points are equidistant
with the distance from Index 4586, Subindex 5. The number of frequency points is
equal to half of the block length used plus 1 and is also given in Index 4586, Subindex
2.
9
OPERATION
42
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
