MRV Communications LX-4000 Series RJ-45 Wiring Considerations, Modular Adapters RJ-45 to DB-25

Appendix D - Cabling the LX-4000 Series

NOTE: You would use a "null-modem" cable when making a direct connection between the serial ports of two communication servers (i.e., no modems involved) or other DTE device. For that application, use a DTE-to-DTE cable.

RJ-45 Wiring Considerations

You should give special consideration to the wiring scheme when connecting a device such as a terminal to a LX-4000 Series serial port. The LX-4000 Series is considered a DTE device. To connect to another DTE device such as a terminal, you will need crossover wiring, as shown in Figure 27 and Figure 28. When a DCE device is connected to an LX-4000 Series serial port, straight-through wiring is required, as shown in Figure 29.

NOTE: In general, an ethernet category 3 (CAT 3) or category 5 (CAT 5) may introduce noise due to the crossing of pins 3 and 6 (transmit and receive). Flat eight wire cables are recommended.

Modular Adapters (RJ-45 to DB-25)

You can obtain adapters with male and female DB-25 connectors from MRV. These adapters direct signals from the RJ-45 connector on the cable to the correct pin on the DB-25 connector. Figure 27, Figure 28, and Figure 29 show how devices are cabled when you use these adapters.

Application (see Figure 27): Use RJ-45 to DB-25 to connect your LX-Series unit to a PC.

LX Series

MAXserver

Connector

Female

RJ-45

Crossover Cable

Male

RJ-45

Male RJ-45

Modular Adaptor			DTE Cable
	Female
	RJ-45
		Female
			To DTE
		DB-25

LXMAXsSeriesv		Male RJ-45	Male RJ-45
Connector		Connector	Connector
	1	1		1
CTS/RINGCTS
	2	2		2
DTR
XMT	3	3		3
XMTGND	4	4		4
RCVGND	5	5		5
RCV	6	6		6
DSR *	7	7		7
RTS	8	8		8

Crossover Cable

Female	RJ-45	Female	DB-25		DTE Device
Connector		Connector			Pin Signal
					CTS
1				5
2				20	DTR
3				2	XMT
4				7	GND
5
6				3	RCV
7				8	DCD
8				6	DSR
				4	RTS

MX-151-3028	Adaptor Wiring - MX-350-0181
* (See Note, Page 5.)	(Female	RJ-45 to female	DB-25)

Figure 27 - Adapter Wiring, LX Series to DTE

451-0308 MRV Communications, Inc. www.mrv.com 59