3: Installation and Hardware
XPress DR+ User Guide 20
Figure 3-5. Termination Resistor for 2-Wire Connection

9-Pin RS-232 to Serial RJ45 Cable (P/N 500-103)

The included Lantronix (P/N 500-103) RJ45-DB9F serial cable assumes you are
connecting a typical PC Com port to the XPress DR+ serial port. This cable is pinned to
provide full serial line control to an RS232 DTE device. Lantronix offers a
comprehensive list of cables and adapters to simplify device connectivity to the XPress
DR+. See B: Lantronix Cables and Adapters for a full listing.
Figure 3-6. 9-Pin RS-232 to Serial RJ45 (P/N 500-103) Pinout Table
8 CTS (In) 1 RTS (Out)
1 DCD (In) 2 DTR (Out)
6 DSR (In) 3 TXD
2 RXD (In) 4 Signal Ground
5 Signal Ground 5 Signal Ground
3 TXD (Out) 6 RXD
4 DTR (Out) 7 DSR (In )
7 RTS (Out) 8 CTS (In)
DTE, 9-Pin XPress DR+
Female Serial RJ45
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 or crossed
Ethernet cables. The unit also supports IEEE 802.1d spanning tree, which protects
against the possibility of a network loop.