Net Optics Fiber Mode Converters - Manual (Page 13)

Fiber Mode Converter
9
Configuration Guidelines for Link Fault Signaling (LFS)
Operation
Link Fault Signaling (LFS) circuitry provides visual indication of link
condition on both segments as well as alerting each host DTE when the
remote link (segment) is down.
1. The FMC series converter operates when it receives a link signal from a
device attached to either port 100Base-FX), then turns-on the link signal to the
device on the other (port) segment. Both (F/O) segments must be connected to
the FMC converter before proper link across both segments can be established
AND at least one end device must provide a link signal to initiate link across
all segments.
2. The FMC converter does not auto-negotiate data rate.
If two FMC converters or a combination CCM card and FMC converter are
used in series to connect two twisted pair nodes then:
A. If at least one of the (100Base-FX) ports can initiate the link signal,
then the converter will establish link and properly support the LFS function
across all segments including both FMC converters or CCM/FMC converter
combination in sequence.
B. If both end nodes are using 100/half duplex/full duplex speed selection
ports, pairs of FMC converters or CCM/FMC combinations (with LFS)
connected in series, will work only if both are set to the same speed. If
CSMA/CD is being run; consult the bit time calculation guide for valid
network configurations.
Note: The FMC series does not have a full duplex/ half duplex switch. They
receive and transmit data 10/100Mbps/half/full duplex transparently, up to
OC-3 speeds.