KM SVS2000, Руководство по установке и эксплуатации, Страница: 64 / 89

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2. Press the enter key to access this menu. The display looks like this:
> 1
3. Use the numeric or Arrow Keys to enter the desired value. Press the Enter Key to save the value in
memory. The display acknowledges the entry and returns to:
71 AVERAGInG
4. Press an Arrow Key to scroll to another menu or press the Gross or net Key to return to Run Mode.
72-75 dSp FIlTer paraMeTerS
Vibrations in a vessel can cause changes in the SVS2000’s weight display and outputs, even though no material
is moved, because the vibrations affect the vessel’s structural response. The Sentry™ DSP filter helps to reduce
display and output changes that can result from vibration. The principle behind the filtering follows. The ADC
converter digitizes the signal coming from a sensor and the SVS2000 converts the signal to a ‘raw’ weight. The
SvS2000 picks the first raw weight as a reference median; this is the value that is used in calculating the filtered
weight. As shown in Figure 13, the SVS2000 then compares following raw weights to the reference median, and
recalculates the reference median when either of the following happen:
• the number of successive weights above or below the median exceeds a triggering number
• a weight falls outside of a user-defined window around the reference median When the SvS2000
recalculates the reference median, the filtered weight changes to correspond to the new reference
median.
note that the DSP Filter affects setpoints, current output, and serial output as well as the weight shown on the
display. The DSP Filter has four parameters:
72 DSP Enable DSP enable turns the DSP filter function on and off. The default is On
73 DSP Step
DSP Step is a window of equal weight above and below the reference median. As shown in
Figure 13, example 1, if a large signal change is detected that falls outside of the window,
the SVS2000 immediately moves the location of the reference median to that point. This
allows the SVS2000 to adjust quickly to rapid material movement in the vessel. The default
is calculated by the SVS2000 based on a default step of 10,000 counts and the calibration
parameters. note that the SVS2000 recalculates DSP Step if the system is recalibrated.
74 DSP Qualify
The triggering number of successive weights above or below the median signal value, but
within the DSP Step window. In example 2 shown in Figure 13, DSP Qualify is 3. When
the third successive signal above the median value (but within the DSP Step window)
is detected, the SVS2000 moves the location of the median value to that point (or a
percentage of the distance from the old median as determined by DSP Factor). This allows
the SvS2000 to respond to definite trends in weight changes. The default for DSP Qualify
is 3.