Specific Resistance Signature (Ieee 802.3Af); Capacitor Signature; Pd Connected; Plug And Play" Operation - Avaya P333T-PWR Installation And Configuration Manual

Figure 13.1 Powered Device Detection

Specific Resistance Signature (IEEE 802.3af)

The P333T-PWR applies a low voltage to the power feed pairs and measures the
current. A resistance of 19kΩ to 26.5kΩ is considered valid according to the IEEE
standard; if a valid signature is detected, power is supplied to the port. If not,
Capacitor Signature verification is performed.

Capacitor Signature

The P333T-PWR injects a time-limited 25mA probing signal into each port and
monitors the terminal voltage as function of time. The switch determines the load
type; if the signature is authenticated as that of a valid PD, then power is supplied to
the port.

PD Connected

Once power is provided to a port, it is checked periodically to see if a PD is still
connected. If a PD is disconnected from a powered port, then power is denied to the
port.

"Plug and Play" Operation

Avaya P333T-PWR User's Guide
Start Check
Valid Resistance
Signature?
No
No
Valid Capacitor
Signature?
No
Chapter 13 Avaya P330 Layer 2 Features
Yes
Yes
Apply Power
Yes
PD still
connected?
63