How to Modify Measurement Input Filter(s)

Introduction

Filters concern the measurement input of the weighing sensors.

By default, a unique filter is offered which is defined for the total duration of the weighing action.

To increase the speed/precision performance of weighing, 3 different filters can be used for the same weighing action, as follows:

Each filter can either have:

a sliding average (filtering coefficients from 1 to 11), where the measurement is the average of the last n values
or be of second order (filtering coefficients from 12 to 19), which are referenced by their cut-off frequencies

Measurement Phases

The various phases of a continuous weighing action can be broken down into:

a phase 1, where speed is the prime feature of control precision (High flow)
a measurement refining phase 2 (Low flow)
a final phase 3, where the measurement value differs very little and requires a high level of precision (Residual flow)

Filter Coefficients

The following list gives the meanings of the filter coefficients:

Value	Filter Type	Characteristics
0	none	not filtered
1	sliding average	average of the last 2 measurements
2	sliding average	average of the last 3 measurements
3	sliding average	average of the last 4 measurements
4	sliding average	average of the last 5 measurements
5	sliding average	average of the last 8 measurements
6	sliding average	average of the last 16 measurements
7	sliding average	average of the last 25 measurements
8	sliding average	average of the last 32 measurements
9	sliding average	average of the last 40 measurements
10	sliding average	average of the last 50 measurements
11	sliding average	average of the last 64 measurements
12	second order filter	cut-off frequency at 15 Hz
13	second order filter	cut-off frequency at 10 Hz
14	second order filter	cut-off frequency at 8 Hz
15	second order filter	cut-off frequency at 6 Hz
16	second order filter	cut-off frequency at 4 Hz
17	second order filter	cut-off frequency at 2 Hz
18	second order filter	cut-off frequency at 1 Hz
19	second order filter	cut-off frequency at 0.8 Hz

Procedure

The following table shows the procedure for defining the filter:

Step	Action
1	Access the weighing module configuration screen.
2	If filters F2 et F3 are being used check the Active box in the Threshold check field.
3	Select for each phase, the filtering coefficient using the drop-down menus F1, F2 and F3 in the Filtering field.
4	Confirm the modification with the command Edit → Validate.