Rice Lake iQUBE2 Digital Diagnostic Junction Box - Manual (Page 60)

56 iQUBE 2 Installation Manual
8.0 Appendix
8.1 Digital Filtering
Digital filtering can be used to create a stable scale reading in challenging environments. The iQUBE 2 uses an
advanced adaptive filter which monitors scale statistics to control settling and response times for the desired scale
stability setting. The iQUBE
2 has two parameters related to digital filtering which can be set: sensitivity and threshold .
Digital Filtering Sensitivity
Digital filtering sensitivity (DFSENS) controls the stability and settling time of the scale. The sensitivity parameter
can be set to Heavy, Medium, or Light. A heavy setting will result in an output that is much more stable and will
settle more quickly than that of a light. However, small changes in weight data (on the order of a few grads) on the
scale base will not be seen as quickly.
If the difference in typical subsequent weight values on your scale will be only a few grads then you should use a
light setting. If your application is a truck scale where the changes in subsequent weight values will be on the order
of 100s of grads then a heavy setting will be more appropriate.
Digital Filtering Threshold
Digital Filtering Threshold (DFTHRH) controls the response delay time of a scale. This parameter can be set in the
range of NONE to 15,000. When a new sampled weight value is acquired, the adaptive filter compares the new
value to the previous (filtered) output value. If the difference between the new value and the previous output value
is greater than the DFTHRH parameter (in counts) the adaptive filter output is disabled and the newly acquired
sample value is used for the output.
If the difference between the new value and the previous output value is less than the DFTHRH parameter, the two
values are averaged together using a weighted average based on the amount of the difference, time the system has
been stable, and selected DFSENS value.
To disable filtering, set DFTHRH to none.
8.2 Cell Emulation
Cell emulation allows the output of a failed load cell to be emulated by using the remaining cells in the system to
estimate the value of the failed cell. The calculation of the emulation value depends the calibration type used to cal-
ibrate the scale. The performance of the emulation for the three calibration types: 2-POINT, CORNERMATCH and
SECTIONMATCH may vary drastically by application. The following guidelines are presented to help select the
proper calibration type and get the best possible performance from your scale if emulation is being used.
Cell emulation is not legal for trade.
8.2.1 Section Match
Section match calibration is used primarily on truck scales.
Truck scales use the concept of sections to describe a scale.
A section is a pair of cells directly across from each other
on the scale. In Figure , load cells 1 and 2, 3 and 4 and 5
and 6 make up the three sections of the scale. The trim-
ming/calibration process requires trimming the scale one
section at a time, therefore three calibration measurements
should be made. One between cells 1 and 2, one between
cells 3 and 4 and one between 5 and 6.
Section match works best when both cells in a section have
the same capacity and sensitivity and the load on the scale will normally be placed along the center line of the scale
(with respect to the two cells in a section).
Emulation performance on section match type scales is highly dependent on the ability of the operator to position
the center of gravity of the load along the center line of the scale.
Note
Note
1
2
3
4
5
6
Center line of scale
Figure 8-1. Example of scale sections