This guide provides comprehensive explanations of the elements in selecting and using Power Over Ethernet (PoE) with IP cameras.
Inside this report we cover:
PoE vs Low Voltage
When to Use PoE, When Not
PSEs vs PDs
802.3af vs 802.3at vs 802.3bt
Nonstandard PoE Implementations
Power Consumption vs Specification
Calculating Power Budget
PoE via Switch, MidSpan or NVR
Power Over Ethernet: Single Camera Power/Signal
All cameras need electrical power to operate. Historically, analog cameras were (and most often still are) used dedicated cables and power supplies, separate from the video cable. However, with the advent of IP cameras and PoE, power and signal could be combined on one cable, eliminating the second cable and power supplies, reducing costs.
PoE Almost Always Used
PoE is supported and used, in practice, in almost all professional IP cameras and installations. It is now very rare for cameras to use separate low voltage power, but there are some applications where this is necessary.
Exceptions To PoE Use
There are some exceptions where PoE is not used with IP cameras: