2
DIP Switch on S1
Feature
Default Setting
1
Forced/Preferred
ON
2
Factory use - Do not change
ON
3
TX LinkLoss
OFF
4
FiberAlert
OFF
5
FX Auto-Negotiation
ON
6
FX LinkLoss
OFF
7
Factory use - Do not change
OFF
8
Factory use - Do not change
OFF
LinkLoss, FiberAlert and Link Fault Pass-Through
McBasic-Gigabit includes the troubleshooting features FiberAlert, TXLL, FXLL and
LFPT that help locate
silent failures
on a network. Before attempting to install the
module(s), understand how these features work and react to specific network
configurations.
** WARNING **
Installing modules without understanding the effects of LinkLoss and FiberAlert can
cause functioning units to appear flawed or even non functional.
Link Integrity
During normal operation, link integrity pulses are transmitted by all point-to-point
Ethernet devices. When an IMC Networks media converter receives valid link pulses,
it knows that the device to which it is connected is up and sending pulses, and that
the copper or fiber cable coming from that device is intact. The appropriate “LNK”
(link) LED is lit to indicate this.
The IMC Networks media converter also sends out link pulses from its copper and
fiber transmitters, but normally has no way of knowing whether the cable to the other
device is intact and the link pulses are reaching the other end. The combination of
FiberAlert and LinkLoss allows this information to be obtained, even when physical
access to a remote device (and its link integrity LED) is not available.
FX LinkLoss (FXLL)
FX LinkLoss is a troubleshooting feature. When a fault occurs on the fiber segment of
a conversation, FX LinkLoss detects the fault and passes this information to the
twisted pair segment. If a media converter is not receiving a fiber link, FX LinkLoss
disables the transmitter on the media converter’s twisted pair port. This results in a
loss of link on the device connected to the twisted pair port.
