Rice Lake SURVIVOR LV Series Livestock Ring Scale - Manual (Page 49)

DIGFL1 = n1 DIGFL2 = n2 DIGFL3 = n3
3rd Stage 2nd Stage 1st Stage
Filter Average
Displayed
Va lu e
n3
2nd Stage
n2
1st Stage
n1
A/D Readings
Filter Average Filter Average
Filter Average Filter Average
Appendix 45
Figure 8-4. Flow Diagram for 590 AG Indicator Digital Filters
8.6.1 DIGFLx Parameters
The first three digital filtering parameters, DIGFL1, DIGFL2, and DIGFL3, 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 8-4).
The overall filtering effect can be expressed by multiplying the values assigned to the three filter stages:
DIGFL1 x DIGFL2 x DIGFL3
For example, if the filters are configured as DIGFL1=4, DIGFL2=8, DIGFL3=8, the overall filtering effect is 256
(4 x 8 x 8). With this configuration, each A/D reading has a 1-in-256 effect on the displayed weight value. Setting
the filters to 1 effectively disables digital filtering (1 x 1 x 1 = 1).
8.6.2 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.
8.6.3 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 setup mode, set all three digital filters (DIGFL1, DIGFL2, DIGFL3) to 1. Set DFTHRH to NONE.
Return indicator to normal mode.
2. Remove all weight from the scale, then watch the indicator display to determine the magnitude of vibration
effects on the scale. Record the weight below which all but a few readings fall. This value is used to
calculate the DFTHRH parameter value in Step 4.
For example, if a heavy-capacity scale produces vibration-related readings of up to 50 lb, with occasional
spikes to 75 lb, record 50 lb as the threshold weight value.
3. Place the indicator in setup mode and set the digital filters (DIGFLx) to eliminate the vibration effects on
the scale. (Leave DFTHRH set to NONE.) Reconfigure as necessary to find the lowest effective values for
the DIGFLx parameters.
4. With optimum values assigned to the DIGFLx parameters, calculate the DFTHRH parameter value by
converting the weight value recorded in Step 2 to display divisions:
threshold_weight_value / DSPDIV