Yamaha D2040 D2040 Owners Manual Image - Page 24

EXTERNAL

CONTROL,

RS

-485

NETWORKS

The

RS

-485

is

an

interface

that

makes

possible

multi

point

data

transmission.

It

is

a

standard

established

by

the

U.S.

Electrical

Industrial

Standards

association

(EIA).

The

more

familiar

RS

-232C

standard

is

also

an

EIA

standard.

One

advantage

that

the

RS

-485

standard

has

over

the

RS

-232C

is

that

it

makes

multi

point

data

transmission

possible,

which

means

rapid

parallel

transmission

over

long

distances.

This

standard

is

for

the

connecting

hardware

only,

and

it

does

not

determine

the

transmission

protocol

for

the

data

itself.

That

must

be

done

by

software.

Therefore,

even

if

a

device

is

equipped

with

an

RS

-485

port,

if

the

transmission

protocol

is

not

set

to

the

same

as

the

D2040,

data

transmission

will

be

meaningless.

Cornrow

01)400,plo

n

a

Communication

Format:

EIA

RS

-485

conformity,

unsynchronized

BAUD

Rate:

38.4/9.6

BAUD*

Connector:

XLR type,

male,

female

**

Pin

Assign:

1

Grand

2

Tx+/Rx+

3

Tx+/Rx+

Mark

Space

Start

bit

Stop

bit

r

1

F

I

,

T

T

'

r

''',

r

1

DO1

D1

1

D21

D31

D41

D5

1

D6

1

D7

1

Dp

I

J

_I_

I_

.1

L.

I

-L

A

bus

structure

is

possible

with

the

RS

-485

BAUD

Rate

9600/38400

BPS

Start/Stop

Bit

1

bit

Terminals

I

I

Terminal

Stop

Bit

Data

Bit

Parity

1

bit

8

bits

even

•

Transmission

over

long

distances

is

possible

with

either

a

38400

or

9600

BAUD

rate.

However,

it

is

possible

that

the

quality

of

the

cable

used

for

connection

may

effect

the

transmission.

Be

sure

to

make

the

cable

as

short

as

possible.

Use

only

digital

audio

cables

of

the

following

specifications

when

connecting

peripherals

through

the

AES/EBU

and

RS

-

485

ports:

impedance

-

90

to

120

,

shield

type,

equalized

cable.

If

conventional

audio

cables

(impedance

-

40

to

50

)

are

used,

it

is

possible

that

the

waveform

of

the

transmission

will

be

effected

due

to

signal

reflection

caused

by

impedance

maladjustment,

or

other

problems

will

cause

trouble

and

adversely

effect

the

performance

of

the

unit.

This

is

especially

important

when

connecting

over

distances

of

more

than

10

meters

(32

ft

.)

or

in

multiple

connections.

In

these

cases

the

possibility

of

waveform

deformation

is

greater

than

under

normal

circumstances

and

the

need

for

the

proper

cable

becomes

more

acute.

In

cases

of

distances

of

over

100

meters

(320

ft

.),

it

is

recommended

that

the

resistance

of

the

terminals

be

in

relation

to

the

impedance

of

the

cable

(connect

a

resistor

between

Pin

3

and

Pin

3).

*

To

connect

the

D2040

to

a

unit

equipped

only

with

an

RS-

232C

or

RS

-422

port,

use

a

conversion

box

to

adapt

to

the

RS

-485

standard.

Logic

Pin

2

Pin

3

Mark

1

High

Low

Space

0

Low

High

***

The

standard

BAUD

rate

is

9600,

but

when

higher

speed

transmission

is

required,

38400

can

be

used.

To

facilitate

connection

between

devices,

use

both

male

and

female

connectors.

Except

during

transmission,

the

devices

connected

to

the

RS

-485

bus

are

set

at

high

impedance.

When

you

wish

to

transmit,

check

to

see

if

the

setting

is

high

impedance

and

transmit.

Prevent

the

collision

of

signals

on

the

bus.

"*""

Dp

is

even

parity

bit.

23

Yamaha D2040 D2040 Owners Manual Image - Page 24

External, Control, Networks

Page 24 highlights