Calrec Hydra2, Installation Manual

Page: 34 / 104

34 HYDRA2
Installation Manual
FIBER SFP CONNECTIVITY
Optical SFP modules for fiber
connectivity can be used for console
to processing rack, router to router,
and router to I/O connections.
Fiber connectivity is required when the
cable run between units exceeds the
100m maximum permissible length for
Cat5e/Cat6 copper cabling. Fiber can
also be used for shorter runs if it is the
preferred medium.
Note, this section only concerns fiber
connections made via SFPs. Like all I/O
boxes, MADI units have pluggable SFPs
for their Hydra2 connections to routers,
but they also have fiber connectors that
pass the actual MADI audio format in and
out of the system. The MADI I/O format
fiber connectors are of a fixed type which
has no relation to SFP choice. Different
MADI I/O box build-types are available
to provide various types of MADI fiber
interface. Please refer to “Fixed Format
I/O Overview” on page 44 for more
details on MADI I/O options.
Singlemodevsmultimode
The core within multimode fiber is
relatively thick when compared to
singlemode. Light travels through
multimode fiber at multiple angles,
“bouncing” off the sides of the core as it
travels through it, taking multiple paths
or “modes” of varying length from one
end to the other, resulting in pulses being
lengthened as they travel. Singlemode
fiber has a very fine core through which
light travels in a single, direct path from
one end to the other. without affecting
pulse length. The result is that singlemode
fiber has a higher bandwidth capacity and,
importantly, low signal loss allowing much
longer distances to be achieved. Light
can be transmitted into multimode fiber
using LEDs or low powered lasers whilst
singlemode requires a higher powered
laser.
Calrec recommends the use of
singlemode fiber whenever possible
in order to maximize the flexibility in
the location of hardware and maintain
uniformity across the system by using a
single type. If a multimode infrastructure is
in place, fiber length, the number of inter-
connects and equipment location become
more important.
SFP modules are available for both
singlemode and multimode fiber types.
It is important to select the correct
SFP for the type of fiber being used
in the installation. If using a mixture of
singlemode and multimode fiber, it is
important to ensure the correct SFPs are
matched to the correct fiber type.
Identification
The release button / handles of
fiber SFPs are color coded—blue for
singlemode, black for multimode. Blue LC
connectors, as shown below, should be
used to terminate singlemode fiber, and
beige colored ones for multimode.
DuplexConnectors/terminations
Standard Calrec fiber SFPs, multimode
and singlemode, all use duplex LC
connectors. The duplex termination
requires two fibers per connection, one
is a send path, the other is a receive path.
When terminating the fiber, the send from
DUPLEX LC FIBERS CORRECTLY TERMINATED A TO B & B TO A
one end should connect to the receive of
the other and therefore they are "cross-
over", terminated A to B and B to A.
Singlestrand,bi-directionalSFPs
To reduce the amount of fiber, Calrec
can supply singlemode SFPs that send
and receive over a single, or simplex LC
connector. In order to be able to pass data
in both directions over a single strand, the
light travelling in one direction needs to
be of a different wavelength to the light
travelling in the other direction. Therefore,
bi-directional SFPs come as either type
A, or type B, and they need to be paired
up - A fiber should connect between a
type A and a type B, and not between two
bi-directional SFPs of the same type /
wavelength. SFP modules are color coded
to aid identification between type As &
type Bs.
SFP/fiberspecifications
Specifications are shown in the table
below. The maximum distances shown
assume a single point to point connection
with no intermediary interconnections.
Losses should be measured across the
total signal path including interconnects -
between points of transceiver connection.
Losses need to be less than the optical
power budget of the SFP transceivers
being used.
SFP / FIBER SPECIFICATIONS
BI-DIRECTIONAL LC FIBER CORRECTLY CONNECTED, TYPE A TO TYPE B
SFP type Connector Power Budget Fiber type Max Distance
SX Multimode LC Duplex 7.5dB
62.5/125µm 275m
50/125µm 550m
LX Singlemode LC Duplex 8dB 8/125µm 10km
LX Singlemode bi-di LC Simplex TBC 9/125µm 10km
LH Singlemode LC Duplex 23dB 8/125µm 70km