3 setting the digital filter parameters, 8 analog output calibration, Setting the digital filter parameters – Rice Lake IQ Plus 355 Installation Manual V1.17 User Manual

Page 47

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Appendix

43

7.7.3

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

In the example in Step 2, with a threshold

weight value of 50 lb and a display division

value of 5lb:

50 / 5lb = 10DD.

DFTHRH

should be set to 10DD for this example.

5. Finally, set the DFSENS parameter high

enough to ignore transient peaks. Longer

transients (typically caused by lower vibration

frequencies) will cause more consecutive

out-of-band readings, so DFSENS should be

set higher to counter low frequency transients.
Reconfigure as necessary to find the lowest

effective value for the DFSENS parameter.

7.8

Analog Output Calibration

The following calibration procedure requires a

multimeter to measure voltage or current output from

the analog output module. If the option is not already

installed, see Section 2.4 on page 7.

NOTE: The analog output must be calibrated after the
indicator itself has been configured (Section 3.0
) and
calibrated (Section 4.0
).

Figure 7-5. Analog Output Menu

1. Enter setup mode and go to the ALGOUT

menu (see Figure 7-5).

Set OFFSET to 0% for 0–10 V output,

20% for 4–20 mA output

Set MIN to lowest weight value to be

tracked by the analog output

Set MAX to highest weight value to be

tracked by the analog output

2. Connect multimeter to analog output:

For voltage output, connect voltmeter

leads to pins 3 and 4

For current output, connect ammeter

leads to pins 1 and 2

3. Adjust zero calibration: Scroll to the

TWZERO parameter. Check voltage or

current reading on multimeter. Press and hold

or to adjust the zero value up or down.

The minimum setting should be 50mV above

true zero to prevent erratic output at zero.

4. Adjust span calibration: Scroll to the

TWSPAN parameter. Check voltage or

current reading on multimeter. Press and hold

or to adjust the span value up or down.

5. Final zero calibration: Return to the

TWZERO parameter and verify that the zero

calibration has not drifted. Press and hold

or to re-adjust the zero value as required.

6. Return to normal mode. Analog output

function can be verified using test weights.

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