Fiberplex WDM16, User Manual

Video

Optimization

The

Society

of

Motion

Picture

and

Television

Engineers,

or

SMPTE,

is

a

leader

in

the

development

of

standards

for

film,

television,

and

other

video.

The

Serial

Digital

Interface

or

SDI,

was

standardized

by

SMPTE

for

broadcast

quality

digital

video

transmission.

Other

standards

evolved

from

this

original

standard,

defining

Enhanced,

High

‐

definition

(HD),

3G

‐

SDI

(1080p)

and

Ultra

High

‐

definition

(UHD),

or

4K

video

(2160p).

To

help

ensure

error

‐

free

transmission,

the

standards

include

a

data

scrambler

/

descrambler

to

create

a

high

density

of

transitions

in

the

serial

data,

making

it

easier

for

the

receiver

to

maintain

timing.

Where

an

encoding

method

such

as

8B

‐

10B

ensures

a

minimal

sequential

run

of

all

ones

or

zeros,

it

does

so

at

the

cost

of

a

25%

increase

in

bandwidth

requirements.

The

scrambler

/

descrambler

method

does

not

require

this,

but

as

a

result

there

are

certain

combinations

of

scrambler

state

and

the

next

data

bits

to

be

scrambled

that

result

in

a

sequence

of

up

to

twenty

consecutive

ones

or

zeros.

These

sequences

are

referred

to

as

pathological

conditions,

and

are

present

in

specific

shades

of

pink

or

grey.

These

pathological

conditions

may

create

errors

in

transmission

through

typical

AC

coupled

optics,

or

any

other

AC

coupled

interface.

Video

Enhanced

or

SMPTE

Compliant

optics

are

designed

to

accept

these

pathological

conditions,

allowing

the

longer

sequences

of

ones

or

zeros

to

pass

without

error.

The

Fiberplex

Technologies

WDM16

and

WDM8

Active

Coarse

Wave

Division

Multiplexer

has

Video

Enhanced

optics

pre

‐

installed

internally

on

every

port,

ensuring

error

‐

free

transmission

for

all

of

your

video

requirements.

SFP

MSA

Compliance

The

SFP

Multi

‐

Source

Agreement

(MSA)

is

an

agreement

that

was

drafted

among

competing

manufacturers

of

SFP

optical

modules.

The

SFF

Committee

was

formed

to

oversee

the

creation

and

maintenance

of

these

agreements

including

the

SFP

MSA

designated

as

INF

‐

8074i.

This

agreement

describes

a

mutually

agreed

upon

standard

for

the

form

and

function

of

SFP

modules.

However,

not

all

SFPs

produced

are

MSA

compliant.

The

MSA

provides

for

a

transceiver

(TX/RX)

pinout.

Other

industries

such

as

broadcast

had

the

need

for

dual

TX

and

dual

RX

SFP

for

uni

‐

directional

applications

such

as

video.

Naturally,

a

non

‐

MSA

standard

was

introduced

allocating

pinout

assignments

for

dual

output

and

dual

input

I/O

configurations.

In

addition,

the

some

of

the

internal

serial

communication

pins

were

reassigned.

The

unique

design

of

the

WDM16/8

includes

internal

multi

‐

rate,

CWDM

optical

SFPs

which

handle

the

wavelength

allocation

of

the

CWDM.

These

internal

modules

are

MSA

compliant,

thus

the

external

user

accessible

SFP

modules

must

also

be

MSA

compatible.

For

this

reason

you

cannot

use

non

‐

MSA

SFPs

with

the

WDM16/8.

Be

sure

that

any

SFPs

that

you

wish

to

use

with

this

unit

conform

to

the

pinout

in

Figure

9.

Figure

9

Pinout

of

SFP

cage

on

WDM16/8