Parker Vansco - Connecting Various Sensors; Open Collector

58 VMM2404
Application Examples
10.7. Connecting Various Sensors
There are many types of sensors that can be connected to the VMM2404, as
follows:
 Open collector sensors
 Variable resistance sensors
 Variable reluctance sensors
 Switch sensors
 Voltage sensors
 CMOS sensors
 Potentiometer (ratiometric) sensors
Note 1: To optimize the reading accuracy for sensors, dedicate one of the
main ground pins (called GND) as a low-current ground return for all sensors
on the vehicle.
Note 2: When connecting sensors to the VMM2404, use the sensor's
specification to ensure that the VMM2404 is configured correctly for the
sensor.
10.7.1. Open Collector
Open collector sensors are compatible with each type of input on the VMM2404.
Open collector sensors are typically used in applications that require digital or
frequency measurements. They work by pulling voltage down to ground or up to
power when activated, and are basically a switch that turns on and off.
Note: Open collector sensors need a pull-up or pull-down resistor to bias the
state of the sensor when the sensor is not activated. Pull-up and pull-down
resistors are internal to the VMM2404.