16 Advanced functions
FLUXUS F501
16.10 Behavior of the alarm outputs
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UMFLUXUS_F501V1-3EN, 2020-06-30
16.9.3
Defining the hysteresis
A hysteresis can be defined for the alarm output R1. This prevents a constant triggering of the alarm when measured values
fluctuate marginally around the limit.
The hysteresis is a symmetrical range around the limit. The alarm will be activated if the measured values exceed the upper
limit and deactivated if the measured values fall below the lower limit.
If the switching condition
MAX
or
MIN
is selected in the scroll list
func
:
• Enter a value for the hysteresis or enter zero to work without hysteresis.
• Press ENTER.
16.10 Behavior of the alarm outputs
16.10.1 Apparent switching delay
The measured values and totalizer values will be displayed rounded to 2 decimal places. The limits, however, will be com
-
pared to the non-rounded measured values. This might cause an apparent switching delay when the measured value
changes marginally (less than 2 decimal places). In this case the switching accuracy of the output is higher than the accura
-
cy of the display.
16.10.2 Reset and initialization of the alarms
After an initialization of the transmitter, all alarm outputs will be configured as follows:
Press 3 times key C during the measurement to set all alarm outputs to idle state. Alarm outputs whose switching condition is
still met will be activated again after 1 s. This function is used to reset alarm outputs of the type
HOLD
if the switching condition
is no longer met.
By pressing key BRK, the measurement is stopped and the main menu is selected. All alarm outputs will be de-energized,
independently of the programmed idle state.
16.10.3 Alarm outputs during transducer positioning
At the beginning of the transducer positioning (bar graph display), all alarm outputs switch back to the programmed idle
state.
If the bar graph is selected during the measurement, all alarm outputs will switch back to the programmed idle state.
An alarm output of the type
HOLD
that has been activated during the previous measurement will remains in idle state after
the transducer positioning if its switching condition is no longer met.
The switching of the alarms into idle state will not be displayed.
Example
physical quantity: mass flow rate in kg/h
Low Limit
: 60 kg/h
The unit of measurement of the physical quantity is changed to kg/min. The new limit to be entered is 1 kg/min.
Example
High Limit
: 30 kg/h
Hysterese
: 1 kg/h
The alarm is activated for measured values > 30.5 kg/h and deactivated for measured values < 29.5 kg/h.
R1 Input\...\Hysterese
Tab. 16.2: Alarm state after an initialization
func
OFF
typ
NON-HOLD
mode
NO Cont.
Limit
0.00