Counterpart User Manual - For More Information
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9.6
Digital Filtering
The
Counterpart
uses averaged digital filtering to reduce the effect of vibration on weight readings. Adjustable
threshold and sensitivity functions allow quick settling by suspending filter averaging, allowing the weight
reading to jump to the new value. Figure 9-2 shows the digital filter parameters on the CONFIG menu.
DFLTR1
64
128
4
16
8
32
256
DFSENS
DFTHRH
32OUT
64OUT
2OUT
8OUT
4OUT
16OUT
128OUT
20D
50D
250D
5D
2D
10D
100D
NONE
200D
1
2
DFLTR2
64
128
4
16
8
32
256
1
2
DFLTR3
64
128
4
16
8
32
256
1
2
Figure 9-2. Digital Filtering Parameters on the Configuration (CONFIG) Menu
DIGFL1= n1
DIGFL2= n2
DIGFL3= n3
3rd Stage
Filter A verage
2nd Stage
Filter A verage
1st Stage
Filter A verage
Displayed
Value
n3
2nd Stage
Filter A verages
n2
1st Stage
Filter A verages
n1
A/D Readings
Figure 9-3. Flow Diagram for
Counterpart
Digital Filters
9.6.1
DIGFLx Parameters
The first three digital filtering parameters, DFLTR1, DFLTRL2, and DFLTR3, are configurable filter stages that
control the effect of a single A/D reading on the displayed weight. The value assigned to each parameter sets the
number of readings received from the preceding filter stage before averaging (see Figure 9-3).
The overall filtering effect can be expressed by adding the values assigned to the three filter stages:
DFLTR3
For example, if the filters are configured as DFLTR1=4, DFLTR2=8, DFLTR3=8, the overall filtering effect is 20
(4 + 8 + 8). With this configuration, each A/D reading has a 1-in-20 effect on the displayed weight value. Setting
the filters to 1 effectively disables digital filtering.
9.6.2
DFSENS and DFTHRH Parameters
The three digital filters can be used by themselves to eliminate vibration effects, but heavy filtering also increases
settling time. The DFSENS (digital filter sensitivity) and DFTHRH (digital filter threshold) parameters can be
used to temporarily override filter averaging and improve settling time:
•
DFSENS specifies the number of consecutive scale readings that must fall outside the filter threshold
(DFTHRH) before digital filtering is suspended.
•
DFTHRH sets a threshold value, in display divisions. When a specified number of consecutive scale
readings (DFSENS) fall outside of this threshold, digital filtering is suspended. Set DFTHRH to NONE
to turn off the filter override.
9.6.3
Setting the Digital Filter Parameters
Fine-tuning the digital filter parameters greatly improves indicator performance in heavy-vibration
environments. Use the following procedure to determine vibration effects on the scale and optimize the digital
filtering configuration.
1. In menu mode, set all three digital filters (DFLTR1, DFLTRL2, DFLTR3) to 1. Set DFTHRH to NONE.
Return indicator to normal mode.
