Matrox 4Sight EV6 Installation And Hardware Reference page 46

46 Chapter 2: Getting started with your Matrox 4Sight EV6 unit
+
24V
-
Optional because the auxiliary input signals are electrically isolated.
Equivalent circuit only
Connecting a 2-wire proximity sensor to an auxiliary input signal
You can connect a 2-wire proximity sensor to a Matrox 4Sight EV6 auxiliary input
signal in either a sourcing or sinking configuration (that is, on a positive or negative
power wire). Note that in both cases, you will need to install an external bleeder
resistor, to ensure that a minimum amount of current flows into the proximity
sensor in its on-state and in its off-state.
The bleeder resistor's value should guarantee that the minimal required current is
provided to the connected sensor (the third-party device). Typically, a 2.2 KOhm
bleeder resistor should be sufficient. For details regarding the sensor's minimum
current requirements, refer to its documentation. Note that you should use a
bleeder resistor with an appropriate power rating for your circuit.
• For the auxiliary input signal to source the current (that is, to connect an auxiliary
input signal on a positive power wire), connect the 2-wire device to the auxiliary
input signal as shown below. You must also install an external bleeder resistor
between the AUX_INn+ pin and brown wire of the proximity sensor.
Matrox 4Sight EV6
in a sourcing configuration
AUX INn+
Sensing
Circuit
AUX INn-
_
Brown wire
_
Blue wire
2-wire NPN
proximity sensor