2
Gigabit
Compact Media Converter
Installation Guide
About FiberAlert
FiberAlert
is an advanced troubleshooting feature that helps locate "silent fail-
ures" on your network. However, it is vital that you understand exactly how
FiberAlert
works, and how it will react in your network configuration, before
attempting to install the enclosed unit.
Installing modules without understanding the effects of
FiberAlert
can cause perfectly functioning units to appear flawed or even dead
.
W
H A T
I
S
F
I B E R
A
L E R T
?
FiberAlert
minimizes the problems
associated with the loss of one strand of
fiber. If a strand is unavailable, the
Compact Media Converter,
at the receiv-
er end, notes the loss of link. The
device will then stop transmitting data
and the link signal until a signal or link
pulse is received. The result is that the
link LED on BOTH sides of the fiber connection will go out indicating a fault
somewhere in the fiber loop. Using
FiberAlert
, a local site administrator is noti-
fied of a fault and can quickly determine where a cable fault is located.
A
Au
utto
oC
Crro
ossss F
Fe
ea
attu
urre
e ffo
orr TTw
wiisstte
ed
d P
Pa
aiirr C
Co
on
nn
ne
eccttiio
on
nss
The twisted pair port of the
L1 Gigabit
includes
AutoCross
, a feature which
automatically selects between a crossover workstation or pass-through/repeater
hub connection depending on the connected device.
Installation Troubleshooting
•
During installation, first test your fiber and twisted pair connections with
FiberAlert
disabled. Then enable
FiberAlert
, if desired, just before final
installation. This will reduce the feature’s interference with testing.
•
FiberAlert
should only be enabled on one side of a media conversion.
Enabling it on both sides would keep both transmitters off indefinitely.
•
To test
L1 Gigabit
by itself, you must have an appropriate fiber patch
cable. First, connect
L1 Gigabit
to the twisted pair device with a twisted
pair cable. Next, loop a single strand of fiber from the transmit port to
the receive port of your media converter. Finally, verify that you have
both twisted pair and fiber link on your media converter.
• Make sure you are using the appropriate twisted pair cable (i.e. crossover
or pass-through). Gigabit Ethernet requires Cat-5 cabling and patch cords.
Cable Break
XMT
RCV
LED
Remote Site
Local Site
LED OFF = Broken Link
LED
XMT
RCV
Black Box product with FiberAlert Enabled
Remote Site stops transmitting
Local Link LED is OFF indicating a break in the fiber loop
About L1 Gigabit Media Converters
L1 Gigabit Compact Media Converters
are IEEE 802.3 and provide a single-
conversion between 1000Base-TX twisted pair and 1000Base-SX multi-mode
or 1000Base-LX single-mode fiber.
L1 Gigabit
is available with one RJ-45 con-
nector for the twisted pair port and an SC connector for the fiber port.
L1 Gigabit
is a 1U high, standalone unit that includes diagnostic LEDs for each
port and a universal (100/240 VAC) power supply.
L1 Gigabit TX/850SXMM-SC — 1000Base-T twisted pair/1000Base-SX 850 nm multi-mode
fiber; one RJ-45 connector and one pair SC (LGC5134A) connectors.
L1 Gigabit TX/LX SM/PLUS-SC — 1000Base-T twisted pair/1000Base-SX 13100 nm single-
mode fiber; one RJ-45 connector and one pair SC (LGC5135A) connectors.
Installing L1 Gigabit
L1 Gigabit
comes ready to install. The only adjustments that may need to
be made come after installation. To install
L1 Gigabit
, first make sure that the
unit is placed on a suitable flat surface. Attach the cables between the
L1
Gigabit
and each device that will be interconnected, then plug the unit into a
reliable, filtered power source.
Configuring L1 Gigabit
Once installed,
L1 Gigabit
can be configured for
the following features: Duplex Mode, Master/Slave
Mode and
FiberAlert.
D I P S
W I T C H
S
E T T I N G S
L1 Gigabit
features an 8-position DIP switch for
configuring the unit. The switch is accessed through
a cut-out in the bottom of the unit. The following
table provides simplified definitions of the function of each switch.
OFF/ON
FDX/HDX
SLV/MSTR
RESERVED
RESERVED
FA
RESERVED
RESERVED
RESERVED
S1
1
2
3
4
5
6
7
8
D
U P L E X
M
O D E
The Duplex mode settings of the
L1 Gigabit
converter are used with
Auto-
Negotiation
. The default Duplex mode for
L1 Gigabit
is Full-Duplex. In this
mode, Full-Duplex is advertised during
Auto-Negotiation
. To make the unit
operate in Half-Duplex, simply move DIP switch
1
from the
OFF
to the
ON
position. This will allow only Half-Duplex to be advertised during
Auto-
Negotiation
. The
Auto-Negotiation
takes place on the twisted-pair interface
only. When the twisted-pair interface is resolved, the configuration will be
encoded into the fiber side. No auto-negotiation takes place on the fiber side.
As a result, it is usually best to disable
Auto-Negotiation
on the remote fiber
end. Since most gigabit networks run at Full-Duplex, it is recommended to set
the remote fiber end to Full-Duplex.
M
A S T E R
/ S
L A V E
M
O D E
This feature determines which clock will be used between the
L1 Gigabit
and
the device it is connected to (a switch, NIC, or another
L1 Gigabit
, etc.). Master
mode is the default setting, where
L1 Gigabit's
clock is used. To change this to
the Slave setting, move DIP switch
2
to the
OFF
position.
L1 Gigabit
will then
receive and use the clock of the other connected device.
NOTE: The Master/Slave mode is only valid for the twisted pair link.
R
E S E T
B
U T T O N
O
P E R A T I O N
If your unit is running and you change either the Duplex Setting or Master/
Slave mode, you will need to reset your unit before these changes take effect.
The Reset button located on the front faceplate can accomplish this. To reset
the unit, take a slender, non-conductive object, about the width of a paper clip,
insert it into the hole in the chassis, and press the Reset button inside. Please
observe proper ESD procedures when resetting your chassis. Note that power
cycling the unit (i.e. removing the power cord and then reconnecting it) will
also reset
L1 Gigabit
.
Negotiation and L1 Gigabit
L1 Gigabit
will negotiate between Master and Slave mode. To avoid conflicts
with devices connected to
L1 Gigabit
, it senses which mode is appropriate and
will then choose that mode.
L1 Gigabit
also negotiates between Half- and Full-
duplex. Typically, when
L1 Gigabit
is connected to a NIC or switch, it functions
as a Master, as the NIC and switch auto-negotiate and determine which mode
will not cause conflict.
The
L1 Gigabit
should drop down to Slave mode
when connected to a switch or other multi-port device.
When connected to
another
L1 Gigabit
, there is a period of time where, while negotiation is taking
place, errors may be seen. After a short period of time, the device returns to
normal operation.
3
1
LGC5134A — LGC5135A
1
1
Duplex Mode (ON: Half-Duplex, OFF: Full-Duplex)
O
OF
FF
F
2
2
Master/Slave Mode (ON: Master, OFF: Slave)
O
ON
N
4
4
FiberAlert
O
OF
FF
F
3
3,, 5
5--8
8
Factory Use Only —
DO NOT CHANGE
N
N//A
A
S
WITCH
F
UNCTION
D
EFAULT
