How to communicate to SEN0395 using UART?

First and foremost how do I communicate to sensor using UART? Like what physical hardware do I need in order to be able to send and read the serial data from the SEN0395?

Can I use Arduino to communicate via UART to communicate to the sensor? I hooked up the sensor RX to arduino RX (pin 0) and sensor TX to arduino TX (pin 1) and opened serial monitor and typed sensorStop but I got no response back. I tried all sorts of commands (sensorStart, detRangeCfg, outputLatency, resetSystem, etc.) and nothing is happening. 

I want to reduce the sensitivity so that it only detects 0-15cm motion and presence (I need it to act like a sensor that will be inside a wooden step to detect when to activate lights) 

I dont understand how can I use UART to communicate with device…? Please assist