451-0308
MRV Communications, Inc.
www.mrv.com
61
Appendix D - Cabling the LX-4000 Series
Figure 30 - Adapter Wiring, LX-Series to DCE, with RING
NOTE:
In order to expand the functionality of the serial interface, the LX-4000 Series modular
cabling allows you to connect different signals to pin 7 of the LX-4000 Series. (This pin is an
input to the LX-4000 Series.) When a DCE device is connected to an LX-4000 Series serial
port, the device's DCD output is connected to pin 7. In this case, the signal at pin 7 is
referred to as DCD. DCD is used here for session control only, not for flow control.
When a DTE device is connected to an LX-4000 Series serial port, the device's DTR output is
connected to pin 7 of the LX-4000 Series. In this case, the signal at pin 7 is referred to as
DSR. (This cabling scheme also provides DECconnect compatibility, since DECconnect does
not support the DCD signal.)
MRV 8-Wire Cabling
This cabling scheme provides XMT, RCV, DCD/DSR, DTR, RTS, CTS, and two signal ground wires.
This cabling is provided through RJ-45 connectors. Using this cabling scheme you can concurrently
use modem control and RTS/CTS hardware flow control, since there are four control signals. This
scheme is useful with relatively high speed devices, complex modem control applications.
In Figure 31, one signal is referred to as CTS. The CTS signal designation refers to the signal
observed at pin 1 of each serial port. Pin 1 is multiplexed to these signals.
This scheme is useful with the following applications:
LX Series
Connector
Female
RJ-45
Male
RJ-45
Male
RJ-45
Straight Through
Cable
Female
RJ-45
Modular
Adaptor
Modem
Cable
Male
DB-25
To Modem
1
2
3
4
5
6
7
8
22
20
2
7
3
8
4
5
Female RJ-45
Connector
Male DB-25
Connector
DCE Device
Pin Signal
RI
DTR
TXD
GND
RXD
CD
RTS
CTS
Adaptor Wiring MX-350-0179
(Female RJ-45 to male DB-25)
1
2
3
4
5
6
7
8
Male RJ-45
Connector
CTS
DTR
XMT
GND
GND
RCV
DCD
RTS
Straight Through Cable
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
Male RJ-45
Connector
LX Series
Connector
Supports RING
MX-151-3027
