Use industrial-standard network cables such as Cat5e and Cat6 to connect the switch to various terminal devices such as sensors, controllers, PLCs, and higher-level network devices such as routers and firewalls. Use red wires for positive, and black wires for negative. Take the red wire, and connect the positive connection of the. Below is a step-by-step guide on how to install an industrial PoE ethernet switch, covering the entire process from preparation to final testing: 1. Preparation and Planning Before you begin installation, make sure to thoroughly prepare by considering the following: a.