Allied Telesis AT-GS900/8PS manual Wiring Implementation

Wiring Implementation

AT-GS900/8PS Switch Installation Guide

The IEEE 802.3af standard defines two methods by which a PSE, such as the switch, can transmit DC power over twisted pair cables to PDs. These methods, known as Alternatives A and B, identify the wire strands the switch should use when sending DC power to a PD. The AT-GS900/8PS switch delivers power using Alternative A.

Twisted pair cabling typically consists of eight strands. With 10Base-T and 100Base-TX devices, the strands connected to pins 1, 2, 3, and 6 on the RJ-45 connectors carry the network traffic while strands connected to pins 4, 5, 7, and 8 are unused. With 1000Base-T devices, all eight strands are used to carry network data.

It takes four strands to deliver DC power to a PD. With Alternative A, the power is delivered on pins 1, 2, 3, and 6. With Alternative B, the power is provided over the strands connected to pins 4, 5, 7, and 8.

The ports on the AT-GS900/8PS switch delivers the power using pins 1, 2, 3, and 6, which corresponds to Alternative A in the IEEE 802.3af standard.

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