Matrox 4Sight EV6 Installation And Hardware Reference page 33

Connecting to a
digital device that
requires two
predictable voltage
levels to operate
Equivalent circuit only
The auxiliary 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
predictable voltage levels to operate, pullup circuitry must be added.
Connection required if using
external pullup circuitry
+
Up to 24V
-
Optional.
To add pullup circuitry, attach an external pullup resistor. A resistance value
between 2.2 and 5 KOhms, is suggested to protect your Matrox 4Sight EV6. Since
your Matrox 4Sight EV6 auxiliary output signals can sink up to 100 mA, use the
documentation of your input to calculate the required resistance for your external
pullup resistor (if necessary).
In the connections above, the pullup circuitry causes an inversion if the input of
the device is connected to the AUX_OUTn+ pin. When the auxiliary output
signal is on, the circuit between its AUX_OUTn+ and AUX_OUTn- pins is
closed, and current flows from the power source to the AUX_OUTn- pin. So the
observed voltage at the AUX_OUTn+ pin will be low. Whereas, when the auxiliary
output signal is off, the circuit between its AUX_OUTn+ and AUX_OUTn- pins
is open, and current flows from the power source to the input of the device.
Connecting to the auxiliary I/O interface
AUX OUTn+ _
AUX OUTn- _
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