[email protected] | Installation manual Omnicomm 2.0 terminals v2.2
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Method of calculation of calibration coe
ffi
cient. It is necessary to convert the number of impulses into shaft
speed (in revolutions/min). Data collection timer is 30 s.
• four impulses come per shaft rotation, i.e., to determine the number of turns, it is necessary to
multiply the number of impulses by 0.25.
• The Terminal sums the number of impulses for the period of «data collection timer» - in our case,
for
½
minute (30 s) - and in order to obtain the number of revolutions per minute, it is necessary
to multiply the number of revolutions for data collection timer by two.
• the resulting input calibration coe
ffi
cient: 0.25 x 2 = 0.5
Example 4. Potential sensor for lifting control of dump truck body (option 1)
Purpose: control of lifting the body of a dump truck.
Let us consider the option of using a contact sensor (similarly, a proximity sensor of any operational type
may be connected), bearing in mind that the sensor contacts disconnect, when the dump truck body is
lifted.
The sensor is connected according to Figure 95.
The following parameters must be preset in Omnicomm Con
fi
gurator:
Parameter
Value
Input type
Potential
Voltage threshold for actuation (V)
4.5
Pull-up resistor
YES
Inversion of potential signal
NO
Explanation:
• With closed contact of the sensor, voltage, close to 0 V (“ground” voltage), occurs at the input
of the Omnicomm Terminal. When contact is broken, voltage with a value, close to the supply
voltage value, is delivered via actuated pull-up resistance. Therefore, you must set the threshold
for switching between zero and the value of the supplied voltage, for example, leave the default
value at 4.5 V.
• The sensor contacts are opened when lifting the body.
With closed contacts, at Omnicomm Terminal input, voltage of approximately 0 V (Terminal input
is grounded) is less than the value of “Voltage threshold for actuation” and is recognised as the
deactivation signal (logical “0”).
When sensor contacts are broken, voltage is supplied to Terminal input via a pull-up resistor;
the value of the voltage is greater than the value of “Voltage threshold for actuation” and is
recognised as the activation signal (logical “1”). Consequently, it is not required to invert the
signal. If sensor contacts are closed when lifting the body, it would be necessary to actuate the
inversion of the signal.
Example 5. Potential body dump truck lifting control sensor (option 2)
Purpose: control of lifting the body of a dump truck.
For control measure, pressure sensor with analog output signal, embedded in a hydraulic main line of body
lifting mechanism, is used. However, the sensor is not con
fi
gured as an analog sensor, but as a potential
sensor.
