6
Hysteresis function
Window function
FL
FH
SP = set point
rP = reset point
HY = hysteresis
Hno / Fno = NO (normally open)
FH = upper limit value
FL = lower limit value
FE = window
Hnc / Fnc = NC (normally closed)
When the hysteresis function is set, the set point (SPx) is defined first and
then the reset point (rPx) which must be of a lower value� If only the set
point is changed, the reset point remains constant�
When set to the window function the set and reset points have a fixed hys-
teresis of 0�25 % of the final value of the measuring range� This keeps the
switching status of the output stable if the volumetric flow varies slightly�
4.2 Analogue function
The unit provides an analogue current signal that is proportional to the volumetric
flow quantity and the medium temperature� Within the measuring range the output
signal is between 4 and 20 mA� Outside the measured and displayed value range
or in case of a fault the signals < 4 mA or > 20 mA are provided (→ Figures).
Caption:
1: Output current in mA
2:
Volumetric flow quantity (final value of the measuring range MEW = 100 %)
3: Medium temperature
4: Measuring range
5: Display range
6: The unit is in the error state (FOU = OFF)
7: The process value transmitted in an analogue way is therefore above the display range
8: The unit is in the error state (FOU = ON)
