Microscan HAWK MV-4000, Manual

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Connecting to the I/O Interface
System Components
2
HAWK MV-4000 Smart Camera Guide 2-21
Connecting to a Digital Device That Requires Two Predictable
Voltage Levels to Operate
The output signals can, therefore, only present one predictable voltage level for a given
configuration: a low voltage level in a sinking configuration or a high voltage level in a
sourcing configuration. Their other output state is, by default, floating. So, if you need to
connect to a digital device that requires two predicable voltage levels to operate, pull-up or
pull-down circuitry must be added.
(Equivalent circuit only.)
To add pull-up or pull-down circuitry, attach an external pull-up or pull-down resistor,
respectively. A resistance value of 3 KOhms is suggested to protect your HAWK MV-4000.
Since your HAWK MV-4000 output signals can sink up to 50 mA, use the documentation
of your input to calculate the required resistance for your external pull-up/pull-down
resistor (if necessary).
In the connections above, the pull-up circuitry causes an inversion if the input of the device
is connected to the Output pin. When the output signal is on, the circuit between its Output
pin and Output Common pin is closed, and current flows from the power source to the
Output Common pin. So the observed voltage at the Output pin will be low. Whereas,
when the output signal is off, the circuit between its Output pin and Output Common pin is
open, and current flows from the power source to the input of the device. In this state, the
current is limited by the pull-up’s resistor value.
Warning: The HAWK MV-4000 output signals are compatible with voltages up to 24 V.
However, by default, the output signals offer low resistance. When they are on (their circuit
is closed), current flows directly through them. Ensure that the circuit created between the
power source, the output signal, the connected device, and return path does not cause
more than 50 mA to flow through the signal.