As I understand IEEE PoE standards, the PSE detects PoE capability of the connected device (PD) by measuring resistance on certain pairs and then negotiates its PoE requirements.
- Do passive PoE PSE perform the measurement before outputting power?
- Is there any PoE injector or midspan PSE that does so?
- Is there a risk of damaging equipment when connecting a non-PoE device down the line of passive PoE injector? Do Ethernet controllers include any protection against such damage? (thinking laptop, basic switch...)