IEEE 802.3bt standard devices are backwards compatible with previous PoE standard devices, IEEE 802.3at and
IEEE 802.3af, allowing existing PoE devices to deliver or receive power up to their maximum IEEE 802.3 PoE
classification.
The 2930M switches provide modular stacking, modular 10GbE, 40GbE, or Smart Rate multi-gigabit ports, and
hot-swappable power supplies for redundancy, up to 60W PoE per port (up to 1440W PoE total**) for powering
APs, cameras, and IoT devices.
NOTE:
** The front panel ports are able push up to 60W of PoE per port. For 1440W PoE, 2x
JL087A Aruba X372 54VDC 1050W 110-240VAC Power Supplies must be installed.
NOTE:
The 802.3bt support is available only on two switch models of 2930M, R0M67A and
R0M68A.
The following Aruba 2930M models provide up to 60W PoE per port** and are compatible with IEEE 802.3bt
standard (Class 6):
• Aruba 2930M 40G 8 Smart Rate PoE Class 6 1-slot Switch (R0M67A) - 36 1GbE ports; 8 Smart Rate ports (1,
2.5, 5, 10GbE); 4 dual personality ports (1SFP, 1G BASE-T - includes PoE)
• Aruba 2930M 24 Smart Rate PoE Class 6 1-slot Switch (R0M68A) - 24 Smart Rate ports (1, 2.5, 5GbE)
Some of the advantages of 802.3bt support includes:
• Reduced power loss since power is transferred from PSE to PD over all 4 pairs of wires.
• Backward compatible with 802.3af and 802.3at PDs.
• Support for Dual Signature PDs.
• Require the PD to draw a minimum amount of power to keep the connection active, 10mA minimum load.
802.3bt allows for smaller MPS pulse current and larger interval between pulses. With these changes,
significant power savings is possible in large deployments involving tens of thousands of PoE ports where both
the PSE and PD are 802.3bt compliant. The power savings that can be accomplished is big for the industrial
lighting.
Definition of terms
Term
Definition
Detection Signature
Resistance of PD during detection.
Classification Signature
Used by PSE to identify the PD device type and vice
versa.
MPS
Maintain Power Signature
Dual Signature (DS) PD
Has independent detection signatures, classification
signatures, and MPS on each pair set.
Single Signature (SS) PD
Shares the same detection signature, classification
signature, and MPS between both pair sets.
PLC
Physical Layer Classification
DLC
Data Link Layer Classification
Chapter 4 Power Over Ethernet (PoE/PoE+) Operation
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