RJ-45 Wiring Considerations. MRV Communications LX-4000 Series

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.

Connector

Female

RJ-45

Male

RJ-45

Crossover Cable

Male

RJ-45

Modular Adaptor

Female

RJ-45

DTE Cable

Connector

DTR

XMT

XMTGND

RCVGND

RCV

DSR *

RTS

5

6

3

4

1

2

7

8

Male RJ-45

Connector

5

6

3

4

1

2

7

8

Crossover Cable

Male RJ-45

Connector

6

7

4

5

8

1

2

3

MX-151-3028

* (See Note, Page 5.)

Female RJ-45

Connector

3

4

1

2

5

6

7

8

Female

DB-25

To DTE

Female DB-25

Connector

DTE Device

Pin Signal

5

20

2

7

CTS

DTR

XMT

GND

3

8

6

4

RCV

DCD

DSR

RTS

Adaptor Wiring - MX-350-0181

(Female RJ-45 to female DB-25)

Figure 27 - Adapter Wiring, LX Series to DTE

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MRV Communications, Inc. www.mrv.com

59

Appendix D - Cabling the LX-4000 Series

Application (see Figure 28): Use RJ-45 to DB-9 to connect your LX-Series unit to a PC or other serial

port using a D sub-9 connector.

Connector

Female

RJ-45

Male

RJ-45

Crossover Cable

Male

RJ-45

Modular Adaptor

Female

RJ-45

Female

DB-9

Connector

CTS/RING

DTR

XMT

XMTGND

RCVGND

RCV

RTS

7

8

5

6

3

4

1

2

7

8

5

6

3

4

1

2

Male RJ-45

Connector

Crossover Cable

MX-151-3028

* (See Note, Page 5.)

Male RJ-45

Connector

5

6

7

8

3

4

1

2

Female RJ-45

Connector

7

8

8

3

4

1

2

5

6

To DTE

Connector

5

8

4

2

DTE Device

Pin Signal

CTS

DTR

XMT

GND

RCV

DCD

6 DSR

Figure 28 - Adapter Wiring, RJ-45 to DB-9, LX Series to DTE

Application (see Figure 29): Use LX-Series to DCE to connect your LX-Series unit to a modem.

LX Series

Connector

Modular

Adaptor

Modem

Cable

Male

RJ-45

Straight Through

Cable

Male

RJ-45

Female

RJ-45

Fem ale

RJ-45

Male

DB-25

To Modem

Supports RTS/CTS

LX Series

Connector

Male RJ-45

Connector

CTS

DTR

XMT

GND

GND

RCV

DCD

RTS

3

4

1

2

5

6

7

8

1

2

3

4

5

6

7

8

Male RJ-45

Connector

6

7

4

5

8

1

2

3

Female RJ-45

Connec tor

6

7

4

5

8

1

2

3

Male DB-25

Connector

DCE Devic e

Pin Signal

2

7

5

20

CTS

DTR

XMT

GND

3

8

4

RCV

DCD

RTS

Straight Through Cable

MX-151-3027

Adaptor Wiring MX-350-0180

(Female RJ-45 to male DB-25)

Figure 29 - Adapter Wiring, LX Series to DCE

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MRV Communications, Inc. www.mrv.com

451-0308