KROHNE TIDALFLUX IFM 4110 PF EN User Manual

Page 47

7.30830.32.00

Resetting the signal converter, see sections 4 and 5.
When changing the signal converter settings, the green LED (normal) and the red LED (error) on the front panel of the
signal converter start to flash rapidly and frequently. This indicates that the A/D converter range is frequently exceeded and
that not al measured values are evaluated.
Change the following settings to allow the display ripple to be properly evaluated:
Select “BARGRAPH” in Fct. 1.04 DISPLAY, subfunction “DISP. FLOW” and select “YES” in submenu “DISP. MSG.”.
Press

↵

key 4 times to return to measuring mode.

The following displays are possible in measuring mode:
ADC = A/D converter range exceeded
and
OVERFL. I,P and/or P2 = one or several output ranges exceeded

Change procedure A

PLEASE NOTE:
After each of the following changes check if the display and outputs are unsteady in measuring mode. Do not proceed to the
next step unless the display and outputs continue to be unsteady.

•

Fct. 1.02 TIMECONST. (change time constant)

Set to “ONLY I”; set to “ALL” when pulse output is also unsteady.

Set time constant to approx. 20 seconds, check if display remains unsteady and correct if necessary.

•

Fct. 3.06 APPLICAT.

Check if setting in subfunction “FLOW” is “PULSATING.

When the green LED and red LED continue to flash, change the setting of subfunction “ADC GAIN” to “30”.
Should the green LED and the red LED continue to flash frequently, set value to “10”.

If display and outputs continue to be unsteady or if the set time constant proves too high for your specific application (Fct.
1.02) please proceed as described in change procedure B.

Change procedure B

PLEASE NOTE:
Do not proceed according to change procedure B unless the steps of change procedure A proved unsuccessful.

The following settings result in a modified dynamic behavior of the system which is no longer defined by the setting of the
time constant in Fct. 1.02.

•

Fct. 1.02 TIMECONST.

Change setting to 3 seconds.

•

Fct. 3.06 APPLICAT.

Select “YES” in subfunction “SPEC. FILT.” to activate a special noise filter.

Subfunction “LIMIT VAL.” defines a window with a width (somewhere around the mean flow) equivalent to the
value in PERCENT of the full-scale range Q

100%

set here (Fct. 3.02, subfunction “FULL SCALE”).

This value must always be a lot smaller than the amplitude of the display ripple (peak to peak).
Example:

full-scale range Q

00%

500 m

/hr

ripple mean value

25 m

/hr =

5% of full-scale range Q

100%

set amplitude to e.g.

Signals outside the

±± LIMIT VALUE window are cut off (clipping). When e.g. interferences cause the measuring

value to leave this window for a short time, the rate of change of the display and outputs is limited to…

∆

max

∆

T [% / s] = LIMIT VAL. / TIMECONST. (Fct. 1.02)

formula applying to the above example:

∆

max

∆

T [% / s] = 2 % / 3 s = 0.66 % / s.

The delay required for passing on major changes of flow to the display and outputs is defined in subfunction “LIMIT CNT.”.