PoE vs PoE+: what's the actual difference?

PoE and PoE+ both deliver power and data over one Ethernet cable, so a network encoder or decoder needs no separate power supply, only a cable to the switch. The difference is how much power the cable carries. Standard PoE (IEEE 802.3af) supplies up to 15.4 W at the switch port, of which up to 12.95 W is available to the device. PoE+ (IEEE 802.3at) supplies up to 30 W at the port and up to 25.5 W to the device. That figure decides which devices a port can run.

In practice, most compact converters run on standard PoE. An audio converter such as the Pro Convert Audio DX draws about 5 W, and an NDI encoder such as the Pro Convert HDMI Plus about 8 W. Both sit well inside the 802.3af limit. Devices that do more need PoE+. The Pro Convert IP to AIO 4K decoder draws up to about 15.1 W, which is more than standard PoE can deliver, and the Ultra Encode AIO encoder is also a PoE+ device.

The risk runs in one direction. A PoE+ switch will power a standard PoE device without trouble. A PoE+ device plugged into an older switch that supplies only standard PoE may not power on at all, or may not run reliably. Check the per-port PoE rating of your switch before you standardise on a PoE+ device. Check the switch's total PoE budget too, because the power available across all ports combined is limited and a rack of devices adds up quickly.