Vansco VMM3120, User Manual, Page: 30 / 92

20 VMM3120
Inputs
The following shows how to address ground shift with sensors that have dedicated
ground wires:
Figure 9: Analog input with ext. pull-up for sensors with ground wire
To reduce ground shift for sensors that don't have dedicated ground wires

Connect a ground wire from the sensor's mounting location to analog input 1.
Analog input 1 can be configured as a negative amplifier, allowing it to detect
a difference between the voltage of the VMM3120 ground and the voltage of
the sensor ground (the difference is the ground shift).
Note: Sensors that don't have dedicated ground wires are typically grounded
to the vehicle chassis through the sensor's body.