Whenever you see a box with a few Ethernet ports, it’s either referred to as a router, or a switch, sometimes people will even use the word “hub”! Fortunately, it’s simpler than it may seem.

The networking product is suitable for process plants with fast Ethernet infrastructure in hazardous areas. The series 9721 switches have four FX ports for optical fiber cables with the “op is” ...

Each pair has to be put through a transformer for the Ethernet port to work properly, as a rule. That’s the black epoxy-covered block you will inevitably see near an Ethernet port in your device.