Instruction manual

4
Troubleshooting Features
The McBasic 10/100 media converters include two advanced troubleshooting
features to help locate “silent failures” on the network.
• Transparency
• Link Fault Detection (LFD)
Transparency
Transparency is only available in Auto Negotiation mode; it is not available in either
of the two Force modes. When the 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. 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:
• S6 (AN/PNP) must be ON
• S5 (LFD), S7 (Force) and S8 (10 or 100) must be OFF
Link Fault Detection (LFD)
Link Fault Detection (LFD) 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 interfaces 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 the 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
• S7 to ON with either S8 ON for 10 Mbps or S8 OFF for 100 Mbps
• S6 must also be ON
NOTE
When using the LFD feature, if the DIP Switches are in any other combination than listed
above, the McBasic 10/100 may exhibit erratic behavior.