LINK FAULT DETECTION FEATURE
Link Fault Detection is only available when using Force-10 or Force-100
mode; it is not available in Auto-Negotiation mode. When LFD is
enabled and the input link is down at one interface to the McBasic
10/100, the transmitter output on that interface is turned off for about
425ms every 3.8 seconds (i.e. blinking). It applies to both network inter-
faces and to both data rates. If the link at the other interface to the
McBasic 10/100 is also down, there is no output. LFD causes the Link Up
indicator of the link partner to blink.
When McBasic 10/100 is in one of the Force modes, enable LFD by
setting S5 to the ON position. Disable LFD (default) by setting S5 to the
OFF position. In order for LFD to function properly, Force mode must be
enabled by setting S6 and S7 to ON with either S8 ON for 10 Mbps or S8
OFF for 100 Mbps.
TWISTED PAIR CROSSOVER/PASS-THROUGH SWITCH
McBasic 10/100 features a crossover/pass-through push-button switch,
located on the faceplate next to the RJ-45 connector, for setting the
twisted pair connection type (see page 1 for illustration of location).
Select a pass-through connection by pressing the push-button IN. A
crossover connection is selected when the push-button is OUT. If you are
not sure which connection is needed, set the push-button to whatever
setting makes the twisted pair LNK (link) LED glow.
OVERDRIVING SHORT DISTANCE INSTALLATIONS
If attempting to use a high powered device (which is designed for long
distance installations) for a short distance installation, the fiber transmitters
may overdrive the receivers and cause data loss. If this is the case, you
may need to add an optical attenuator to your connection. Please visit
our Web site at www.imcnetworks.com for complete fiber specifications, or
contact IMC Networks for more information.
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NOTE
If you use the DIP switches in any other combination than listed, you may experi-
ence erratic behavior from your module.
• In Force-100 mode, McBasic 10/100 configures specifically as a
100Base-TX/100Base-SX multi-mode or a 100Base-TX/100Base-FX
single-mode fiber media converter; 10 Mbps signals are not accepted.
To enable Force-100 mode, set switch S7 to the ON position, with
switches S6 and S8 in the OFF position.
There is no auto-negotiation in either of the Force modes.
AUTO-NEGOTIATION AND MCBASIC 10/100
When connecting two McBasic 10/100 units between two end stations
(devices such as switches, hubs and repeaters), all devices in the media con-
version should ideally support, and be utilizing, Auto-Negotiation functionali-
ty. While it is possible to have auto-negotiating devices on one side of the
media conversion and fixed (non-auto-negotiating) devices on the other, link
LEDs will react differently depending on where a link fault occurs. Therefore,
IMC Networks recommends you:
A) Set every device in the media conversion for Auto-Negotiation,
or for installations where Auto-Negotiation is not possible from one end of
the media conversion to the other
B) Manually configure all devices for 10 Mbps or 100 Mbps connections
For additional information on Auto-Negotiation and for configuration
examples, please refer to our web site at:
http://www.imcnetworks.com/adocs/support/to-features.pdf
TROUBLESHOOTING FEATURES
McBasic 10/100 media converters include two advanced troubleshooting
features, Transparency and Link Fault Detection (LFD), to help you locate
“silent failures” on your network.
TRANSPARENCY FEATURE
Transparency is only available when using Auto-Negotiation mode; it is not
available in either of the two Force modes. When McBasic 10/100 is auto-
negotiating, Transparency treats the connection between the two end devices
as if there were no media converters installed. For example, in a typical
application where two media converters are installed between two copper-
based switches, the twisted pair cables as well as the fiber cable are seen as
“one” entity. Therefore, if a fault occurs on any segment between the two
end devices, link LEDs on the end devices will go out.
As stated, Transparency is available when McBasic 10/100 is operating in
Auto-Negotiation mode, therefore S6 (AN/PNP) must be ON and S5 (LFD), S7
(Force) and S8 (10 or 100) must be OFF.
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