Roland
Exclusive
Messages
iii
Data
Format
for
Exclusive Messages I
Roland's
MIDI
implementation uses
the
following
data
fonnat
for
all
exclusive messages (type
IV):
Byte
Description
FOH
Exclusive
status
41H
Manufacturer
ID
(Roland)
DEV Device lD
MDL
Model
to
eMD
Command 10
[BODY]
Milln
data
F7H
End
of
exclusive
• MIDI
,tatus,
FOH,
F7H
An exclusive message
must
be flanked by a pair
of
status
codes.
starting
with a Manufacturer - lD immediately
atter
FOH
(MIDI
version1.0).
#
Manufacturer
-10:
41 H
.: Device
-ID
The
Manufacturer -
JD
identifies
the
manufacturer
of
a MIDI
instrument
that
triggers an exc.!usive message. Value 41H
nlDresents Roland's
Manufacturer
-
!D.
DEV
The
Device -
ID
contains a unique value that identi/les the
Individual device
in
the
multiple
implementation
DC
MIDI
instruments.
It
is usually set
to
OOH
- OFH. a value smaller
by
one
than
lhat
of a basic channel. but value
DOH
- 1
fH
may
be used for a device with multiple basic channels.
" Model -
10,
MOL
The
Mooel -
ID
contains a
value
thai uniQuely identLries one
model from another. Different models. however. may
share
an
identical Model - ID
if
they handle similar data.
The
Mode! -
ID
[annat
may contain
DOH
in
one or mare places
to provide
an
extended
data
field.
The
fallowing are examples
of
valid
:o.1odel
-
IDs,
each representing a unique modol:
OIH
02H
O3H
00H.01H
~OH.
02H
OOH.
DOH.
01H
~
Command
-
10:
CMD
;;
Main
data
The
Command -
[Q
indicates
the
function of
an
exclusive
message.
The
Commarn:!
- ID format 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:
BODY
011-1
021-1
03H
OOH.OIB
OOH,
02H
OOH,
DOH,
DIB
This
field contains a message
to
be
exchanged across
an
interface.
The
exact
data size
and
contents will vary with the
Model -
ID
and
Command - ID.
g
Address
- mapped
Data
Transfer
I
Address mapping is a techniQue
[or
transferring messages
conforming to
Ihe 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
speeifies.
Address - mapped data
transfer
is
therefore independent
01
models
and
data
categories.
This
technique allows use
of
two
different
transfer
procedures one - way
transfer
and
handshake
transfer.
.;;
One -
way
transfer
procedure
(See
Section
3
for
details.)
This
procedure Is suited for the
transfer
of a small
amount
of
data.
II
sends
out
an
exclusive message completely independent
of
a receiving device status.
Device
(A)
Device
(6)
MIDI
OUT
~r"c,~.-,,----...,
L....
__
..:.:~=.:.;:.,,'-'~
-2·"~L"='=O="'::.c'
___
-'
Connection
at
point 2 is essential
lor
~
Request
data"
procedures.
(See
Section 3.)
# Handshake -
transfer
procedure
(See
Section
4
for
details.)
This
procedure Initiates a predetermined
transfer
sequence
(handshaking) across the Interface before data
transfer
takes
place. Handshaking ensures
that
reliabiUty
and
transfer
speed
are
high enough to handle a large
amount
of data.
Device (Al
Device
CSl
MIDI
our
j--+j
MIDI
IN
L
__
-,-~=-=",--,!----;--1L"O':·C""::.c'
___
-'
Connection at points 1 and 2 is essential.
Notes
on
the
above
two
procedures
*There
are
separate
Command -
IDs
for different
transfer
procedures.
*Oevices
A and B cannot
exchange
data unless they use Ihe
same transfer procedure,
share
identical Deltiee -
ID
and
Mode!
!D. and are ready for communication.
gr:O:Cn-e-_-w-a-y--C;T;-r-a-n-,-;fe-r---;P:--r-o-c-ed-'-ur-e',
Types
of
Messages
This procedure sends out
data
all the way until it stops
and
Is
used When
the
messages
are
so short thai
answerbacks
ng{."(j
not be checked.
For long
messages. however. the receiving device
must
acquire
each
message
In
Ume
with
the
transfer
sequence. which
insens
intervals
of
at least
20
milliseconds in between.
Message
Command
lD
Request
datil
1
ROI
(11
Hl
Data
set
1
Dn
(12H)
tr
Request
data
#
1:
RQ1
(11
H)
This
message is sent out When
there
is a need to acquire
data
from a device
at
the
other
end of the interface, It comains dat.a
for the address and size that specify designation
and
length,
respectiVely,
of
data
required.
On
receiVing
an
RQl
message. the remote device checks its
memory
for
the data address and size that satisfy
the
requesL
If
it finds them and is ready for communication. the device will
transmit a "Data set 1
(DTJ)"
message, which contains the
requested data. Otherwise. the device will send
out
nothing.
Byte
Description
FOH
Exclusive
status
41H
Manufacturer
ID
(Roland)
DEV
Device
10
MOL
Model
lD
11H
Command
ID
"H
Address
MsB
Ls8
sr
Sila
MsB
LsB
,um
Check;
.um
F7H
End
ot
exclUSive
27
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