CHAPTER 1:
INTRODUCTION
1-4
FOT-F3 USER’S MANUAL
A fiber optic cable is connected to the transceiver through ST
fiber optic ports on the FOT-F3. This provides an optical link to
connect the device to the network.
1.3.2
Distance and Cable Type
The FOT-F3 supports single mode fiber optic cable for sizes
such as 8.3/125
µ
m, 8.7/125
µ
m, 9/125
µ
m, and 10/125
µ
m.
You can also use multimode cable such as 62.5/125
µ
m, but
the signal distance will be much shorter.
The signal distance is dependent on the cable type and the
overall system fiber optic budget. If the system budgets and
timing constraints are met, then a distance of over five
kilometers is possible with single mode cable. However,
Cabletron Systems only supports a distance of 5 kilometers. If
using 62.5/125 multimode cable, signal distance is about 2 km.
An AUI cable, up to 50 meters long, is used to connect an
Ethernet device to the AUI port on the transceiver. The AUI
cable must meet specifications for either IEEE 802.3 or
Ethernet Version 1 or Version 2.
Signal Quality Error (SQE) Test
The FOT-F3 has a Signal Quality Error (SQE) Test Enable
Switch that allows the enabling or disabling of the SQE
(“heartbeat”) test function. The SQE test enables the FOT-F3
transceiver to generate a signal to ensure that the collision
circuit and path are operational between the FOT-F3 and the
Ethernet device attached to the AUI port of the transceiver.
