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Roland
Exclusive
Messages
|j
|Data
Format
for Exclusive
Messages
j
Roland's
MIDI implementation
uses ihG (oflowing data formal
for
ail
exclusive
messages
(type IV)
:
BvtB
Descrtptton
FOH
Exclusive status
41H
Manufacturer
ID
(Roland)
DEV
Devica
^D
MDL
Model
ID
CMD
Command
ID
[BODY]
Main
data
F7H
End
of
exctusivB
;MIDI
status:
FOH.
F7H
An
exclusive
message must
l>e
flanked
by
a
pair
of status codes,
starting
with
a
Manufacturer-ID immediately
after
FOH
(MIDI
versioni.O).
=
Manufacturer
ID
:
41
H
The
Manufacturer-ID
identifies
the
manufacturer
of
a
MIDI
instrument
that
triggers
an
exclusive
message. Value
-llH
represents
Roland's
Manufaclurer-ID.
;
Device-ID
;
DEV
The
Device-ID contains a
unique value
that
identifies
the individual device
in
tfie
multiple
implementation of
MlDi
instruments.
It
is
usually
set
to
OOH
- OFH,
a
value
smaller
by
one
than
that of a basic channel, but
value
0011 -
IFH
may
be used
for a
device with
multiple basic channels.
^ModeMD:
MDL
The
Modei-ID contains
a value that uniquely
identifies
one model
from
another. Different models,
however,
may
share an
identical
Model-ID
if
they
handle
similar data.
The
Model-ID format
may
contain
OOH
in
one
or
more
places
to
provide
an extended
data
field.
The
following are
examples
of valid
Model-IDs,
each
representing
a
unique model
OIH
02 H
03 H
OOH,
OIH
OOH,
02H
OOH, OOH,
om
iCommandID
:
CMD
The Command-ID
indicates the
function
of
an
exclusive
message.
The
Command-ID
formal
may
contain
OOH
in
one
or
more
places
to
provide
an extended data
field.
The
following are
examples
of
valid
Command-
IDs,
each
representing a
unique
function
:
OIH
02H
0311
OOH,
OIH
OOH.
02H
OOH. OOH,
OIH
Main
data
;
BODY
This
field
contains a
message
to
he
exchanged
across
an
interface.
The
exact data
size
and
contents
will
vary with
the
Model-ID
and Command-
ID.
Oneway
transfer
procedure
(See Section
3
for
details.)
This procedure
is
suited
for
the transfer of a small
amount
of data.
It
sends out an
exclusive
message
completeiy
independent
of a receiving
device
status.
Connaotlon
DJagrani
Device (A)
Device
(B)
MIK OUT
MO
IM
MIO
IN
MIDI
OUT
Connection
at
point 2
is
essentia! for
"Request data"
Section
3.)
procedures.
(See
t
Handshake-transfer procedure
(This
device
does not
cover
this
procedure)
This prtKedure
initiates
a predetermined transfer
sequence (handshaking)
across the interface before data
transfer
lakes
piace.
Handshaking
ensures
that
reliability
and
transfer
speed
are
high
enough
to
handle
a large
amount
of data.
CannBction
Diagram
Device
(A)
Device
(B)
MIDI otrr
M?DI IN
'
_
Mia
IN
MIDI
OUT
Connection
at
points
1
and
2
is
essential.
Notes on
the
above
two
procedures
*
There
are separate
Command-IDs
for different transfer
procedures.
*
Devices
A
and
B
cannot exchange
data unless they use the
same
transfer
procedure, share
identical
Device-ID
and Model
ED,
and
are
ready
for
communication.
3
Oneway
Transfer Procedure
This procedure sends out
data
all
the
way
until
it
stops
and
is
used
when
the
messages
are so
short that
answerbacks need
not
be
checked.
For
long
messages, however,
the receiving device
must
acquire
each
message
in
time with
the transfer
sequence,
which
inserts intervals
of
at
least
20
milliseconds
in
between.
Typ«*
of
MiMBgaa
Message
Command
ID
Request
data
1
Data
set
t
RQI
(HH)
DTI
C12H)
Request
data
#1
:
RQI
(11H)
This
message
is
sent
out
when
there
is
a
need
to
acquire
data
from
a
device
at
the other
end
of the
interface.
It
contains data
for
the address
and
size
that specify
designation
and
length, respectively, of
data require.
On
receiving
an
RQI
message,
the
remote
device
checks
its
memory
for
the data
address
and
size
that
satisfy
the
request
if
it
finds
them and
is
ready
for
communication,
the device
will
transmit
a
"Data
set
1
(DTI)"
message,
which
contains the requested data.
Otherwise, the device
will
send out
nothing.
Addressmapped
Data Transfer
Address
mapping
is
a
technique
for
transferring
messages conforming
to
the data
format given
in
Section
I.
It
assigns
a
series
of
memory-
resident
records-waveform and
tone
data,
switch
status,
and
parameters,
for
example-to
specific locations
in
a
machine-dependent
address
space,
thereby
allowing access
to
data
residing
at
the
address
a
message
specifies.
Address-mapped
data
transfer
is
therefore
independent
of
models and
data
categories.
This
technique
allows
use of
two
different
transfer
procedures
:
one-way
transfer
and
handshake
transfer.
Byte
Description
FOH
Excfusive status
dlH
Manufacturer
ID
(Rofand)
DEV
Device
ID
MDL
Model
ID
IIH
Command
ID
aaH
Address
MSB
LSB
asH
Size
MSB
LSB
sum
Check
sum
F7H
End
of
eKclusivB
195
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