Micronor MR380-1-3, Instruction Manual

Page: 19 / 29

MR380-1-3 Instruction Manual
Page 19 of 29
7. Theory of Operation
The “Universal” Controller
The MR380-1-3 Controller is designed to be universally compatible with any standard fiber optic
cabling. This is accomplished through the design of its transmit and receive fibers.
In fiber optics, coupling two fibers of different core diameters is only permitted when the core of
the receiving fiber is the same size or larger than that of the transmitting fiber. For example,
transmitting from OS1 9/125µm single mode fiber to OM1 62.5/125µm or OM2 50/125 multimode
fiber does not produce any losses since the core diameter expands from 9µm to 62.5µm or 50µm.
Conversely, transmitting from OM1 or OM2 fiber to OS1 fiber causes significant losses and is
unacceptable as the core of the receiving fiber is smaller than that of the transmitting fiber.
However, if the receiving fiber is only slightly smaller than the transmitting fiber, there is a smaller
loss that can be built into the system loss budget. For example, transmitting from OM1 fiber
(62.5µm core) to OM2 fiber (50µm core) produces a loss of approximately 1.2dB, which is not a
problem in most situations.
In the MR380-1-3 controller, the transmit fiber is OS1 9/125µm single mode fiber. Since the core
of the fiber is smaller than any other standard fiber, no losses are produced at this connection, no
matter which standard fiber the rest of the system uses. And, at the other end, the controller’s
receive fiber is OM1 62.5/125µm multimode fiber. Similarly, no losses are produced at the receive
connection because the OM1 fiber is larger than any standard fiber the rest of the system might
use.
As a result, the MR380-1-3 controller is compatible with any standard fiber, hence its designation
as a universal controller. Despite this designation, users should use the same fiber throughout their
system to avoid complications and simplify future alterations.