User's Manual

Chapter 3: Installation and Hardware
XPress DR+ User Guide 23
Ethernet Interface
The XPress DR+ includes a two-port unmanaged Ethernet switch with a future option to
migrate to a managed solution.
The internal IEEE 802.3-compliant Ethernet switch is non-blocking, using a 1K MAC
address lookup table with store-and-forward architecture. The XPress DR+ supports
auto-negotiation for 10Base-T or 100Base-TX in both full and half-duplex modes, as well
as automatic MDI/MDIX crossover, allowing use of both straight-through and crossed
Ethernet cables. The unit also supports IEEE 802.1d spanning tree, which protects
against the possibility of a network loop.
Table 3-4. Ethernet Interface Signals
Pin Direction Name Function
TX+ Out 1 Transmit Data +
TX- Out 2 Transmit Data -
RX+ In 3 Differential Ethernet Receive Data +
RX- In 6 Differential Ethernet Receive Data -
The next drawing shows a typical RJ45 connector. The color is not standard but very
typical of an Ethernet patch cable. Pin 1 is located at the top of the connector (orange +
white). The view is from the end of the connector.
Table 3-5.Typical RJ45 Connector
Multi-Drop Ethernet Connections
Although there are two Ethernet ports, the XPress DR+ only has one MAC address and
IP address. Either port can be used as the primary connection with the other used
to inter-connect other Ethernet devices or cascade from one XPress DR+ to another.