IFM Electronic KNM Serie Bedienungsanleitung Seite 11

The unit has a microprocessor which enables optimum adjustment to
the medium. This process can be carried out as often as you like. The
set values are stored in a non-volatile memory (EEPROM) and will be
retained even in case of a permanent power failure. At any time a
value for the empty state, a value for the full state as well as the out-
put function (normally closed or normally open) are stored in this
memory.
The unit has an additional function "uncertain operating range" to
monitor and assess the normal operating status. This function provides
a signal if the internal sensor signal approaches the switch point before
it is actually reached. In this case the red LED is flashing slowly. In clear-
cut applications it should only light for short periods, as the level nears
the switch point.
Important:
This function is not an error message indicating a failure of the unit. It
is to help the user to assess his application. For example it can indicate
switch point drift of the sensor caused by considerable soiling before
malfunctioning occurs, thus allowing a cleaning process to be started
in time or a new empty state setting to be made which takes account
of the soiling.
This function also enables comparison of different mounting positions.
Programming
"Operating mode" is the mode when all the normal sensor functions
are active.
The following settings are also possible on the unit:
• Setting of the switch point by adjustment to the empty and full
states (adjustment mode)
• Setting of the output function as normally closed or normally open
(OES mode)
• Electronic lock to avoid unintentional adjustment (locking mode)
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