Siemens SIWAREX FTC, Руководство по эксплуатации устройства

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W
EIGHING
F
UNCTIONS AND
P
ARAMETERS
5.2.2 DR3 - Characteristic Value Range
Depending on the characteristic value of the connected load cells, the value
1 mV/V, 2 mV/V or 4 mV/V must be selected. Since the SIWAREX FTC supplies
the load cells with approximately 10 V, the measuring input is redefined according
to the expected measurement voltage (max. 10 mV, max. 20 mV or max. 40 mV).
For example, if the characteristic value of the connected load cells is 2.85 mV/V
then the next higher characteristic value must normally be set, i.e. 4 mV/V.
For bi-directional force measurement, the characteristic value range should be
defined as +/-.
5.2.3 DR3 – Filter Sequence for the Signal Filter
Changing the filter sequence can be an advantage in some cases. Normally,
the signal is first filtered by the average value filter.
5.2.4 DR3 - Type of Low-Pass Filters
For the suppression of interference to the weight display, 3 types of filters have
been prepared for selection (critically damped, Bessel filter, Butterworth filter).
The selection is performed empirically. The following images show the step
response of the three filters (fg = 2 Hz).
For the suppression of the interferences in average values, separate filters are
ctivated in the parameters for the respective operating mode. a
FIGURE 5-4 Step responses of the digital low-pass filter
SIWAREX FTC 5-39