Specifications

5.
Alarm Anti-Latch Circuit (stab select at A position)
In some applications,
the Level Genie is used to detect
an object instead of a material level.
Usually, a HIGH-HIGH
program module can be used:
HIGH alarm to detect the object
and in the absence of the object, echoes received from any
target out of HIGH alarm zone will reset the system.
However,
if there is no target to intersect the ultrasonic beam within
10 feet (the maximum range of the Level Genie), no echo will
be received. In this case,
the alarm anti-latch circuit will
unlatch both alarm circuits in less than one second and get
the system ready for the next detection.
This situation may also happen when there is an alarm
in a dusty area and suddenly the material level is moved out
of the alarm region so fast that it causes the loss of echo.
The alarm anti-latch circuit will again unlatch the alarm
(ie. reset the system), when the loss of echo is more than
one second.
(Note:. the minimum delay on the alarms is about
3 seconds).
The system reverts to normal operation under one of three
following conditions:
a.
Whenever a regular echo is being received.
b. Whenever the pump program module is installed.
c.
When stab select is changed from A to B position which is
the standard position (without anti-latch circuit).
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