Digital Filtering; Digflx Parameters; Dfsens And Dfthrh Parameters - Rice Lake Counterpart CP-10 User Manual

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
4
8
16
32
64
128
256
1
2
Figure 9-2. Digital Filtering Parameters on the Configuration (CONFIG) Menu
DIGFL1= n1
n1
A/D Readings
1st Stage
Filter Averages

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:
DFLTR1 + DFLTR2 + 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.
94 Counterpart Counting Scale Indicator
DFLTR2 DFLTR3
4
8
16 16
32 32
64 64
128 128
256 256
1
2
DIGFL2= n2
n2
1st Stage
Filter Averages
2nd Stage
Filter Averages
Figure 9-3. Flow Diagram for
DFSENS
4 2OUT
8 4OUT
8OUT
16OUT
32OUT
64OUT
128OUT
1
2
DIGFL3= n3
n3
2nd Stage
Filter Averages
3rd Stage
Filter Averages
Counterpart
Digital Filters
DFTHRH
NONE
2D
5D
10D
20D
50D
100D
200D
250D
Displayed
Value