WEIGH SCALE BLENDER® - Maguire Products

WEIGH SCALE BLENDER®
MAGUIRE PRODUCTS, INC.
limits, based on the ROV number.
IF ROV equals zero (ROV 10000):
In this (and all) examples, ROV is selecting component 1 as the controlled component.
(ROV 10000)
If RHL is set to any value, the first 3 digits of the parameter indicate a new Regrind setting
to use when the material level is ABOVE the HIGH level sensor; (sensor is covered). The
last 2 digits indicate a new setting to use if material level is BELOW the LOW sensor;
(both High and Low sensors are uncovered).
In other words, RHL allows the selection of a percentage that is HIGHER then normal,
and a percentage that is LOWER then normal. NORMAL is what you put on the bottom
thumbwheel switch.
Sensors are assumed to be covered when NO signal is returned. If a sensor is unplugged
from the controller, it is read as "covered".
If you only have ONE SENSOR, it must be used as a HIGH level sensor. The absence of
a sensor is read as a covered sensor; so the absence of the high sensor would signal the
system to run at the high setting all the time. This would not be acceptable. The absence
of the LOW sensor simple prevents the system from ever thinking it is very low. This is
acceptable.
With a high level sensor only, the system switches between the NORMAL thumbwheel
setting and the HIGH setting indicated by the first 3 digits of the parameter. The last 2
digits have no effect, since a LOW condition is never detected.
Sensors that we supply are wired correctly for this logic. If a "Bindicator" or similar device
is used, with a micro-switch dry contact closure signal, then wire to the normally CLOSED
contact so that the signal OPENS when regrind covers the bindicator paddle.
The circuit board "pin outs" for each sensor are positive, ground, and signal. If you are
wiring using a dry contact closure, only the positive and signal lines are used. When the
contact is open, the signal is pulled to ground internally through a resistor.
Example: RHL is set to 90 and 10 percent (RHL 09010).
ROV last digit is set to zero, (ROV 10000).
The "Regrind" thumbwheel switch is set to 25 percent (025).
The Software logic is as follows:
If material level is high, above the high sensor,
the HIGH sensor is COVERED, (returns NO signal);
Regrind runs at the HIGH setting; 90 percent.
If material level is in the middle, between sensors,
the High sensor is NOT covered, (returns a signal),
the LOW sensor IS covered, (returns NO signal),
Regrind runs at the THUMBWHEEL SETTING; 25 percent.
If material level is low, below the low sensor,
BOTH sensors are NOT covered, (both return a signal),
Regrind runs at the LOW setting; 10 percent.
Edition: March 24, 2008 60