Roland JV-30 Owner's Manual page 59

Roland
Exclusive
Messages
y
pData
Format
for Exclusive
Messagasj
Roland's
MIDI im piemen
la
lion uses the following data format
(or all
exclusive messages {type IV)
:
Byte
Oesciotion
FOH
Exclusive slstus
41H
Manufacturer
ID
(Roland)
OEV
Device ID
MOL
Model
ID
CMD
Command
10
[SODY] Main daia
F7H End
of
.
otcfgsive
a
MIDI status: FOH.
F7K
An
exclusive mcssasc must be flanked by a
pair
of status codes,
startins
Willi a
Manufacturer-ID immediately
after
FOM
(MIDI versionl.O).
s
ManufacturerlD
:
41
H
The Manufacturer-ID
identifies the
manufacturer
o(
a MIDI instrument
that
triggers an exclusive message. Value
4IH
represents
Roland's
Manufacturer-
ID.
e Device ID:
DEV
The DevicclD
contains a
unique value that
idcniifies the
individual device
in
the multiple implementation of
MIDI
instruments,
tt is
usually set to
OOH
-
OFH, a value smaller
by
one than
that
of a
basic
channel, but
value
00)1
-
tFII
may
be used
(or
a device with multiple
basic channels.
s
Model
ID:
MDL
The
Model-ID contains a value
that uniquely identifies
one model from
another.
Different models, however,
may
share
an
identical Model-ID
i(
they handle
similar data.
The
ModeMD
format
may
contain
OOH
in
one
or
more
places to provide
an extended
daia
field.
The following are examples
of valid
Model
IDs.
each representing a unique model
;
out
02H
03H
OOH.
OIH
OOH. 02H
OOH. OOH.
OIH
ttCommantJID:
CMD
The Command-ID
indicates the function
of an exclusive message. The
Command
ID format
may
contain
OOH
in
one or
more
places to provide
an
extended data
field.
The following are examples
ot valid
Command-
IDs,
each representing a unique function
:
OtH
02H
03H
OOH,
OIH
OOH, 02H
OOH. OOH.
OIH
::Main data
:
BODY
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.
[Address
mapped
Data Transfer]
Address
mapping
is
a technique for transferring messages conforming
to the data formal given
in
Section
1. It
assigns
a
series
of memory-
resident
records-waveform and
tone
data,
switch status,
and
parameters,
(or
example~io
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
ot
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
anwunt
of data,
11
sends out
an
exclusive
message
compteicly independent of a
receiving
device
status.
Conn
aot ion
Diagram
Device (A) Oovic*
CB)
WOI OUT
MJO< >N
..
ma
IN
MOOUT
Connection
at
point 2
is
essential for "Request data" procedures. (See
Section
3.)
:
Handshake-transfer procedure
(This device
does
not cover
this
procedure)
This procedure
initiates
a predetermined transfer sequence (handshaking)
across the interface before
data
transfer
lakes
place. Handshaking ensures
thai reliability
and
transfer
speed
are high
enough
to handle
a large
amount
of data
Conntclion Diagram
Device (A) Device
(B)
MIOIOUT
MO m
MOl
in
wa
OUT
Connection
at
points
1
and 2
is
essential.
Notes on the above
two
procedures
*
There
are separate
Command-IDs
(or different transfer procedures.
*
Devices A and B
cannot exchange data unless they use the
same
transfer procedure, share
identical
Device
ID
and Model
ID,
and are
ready
(or
communication.
U
JOne-way 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
noi 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
M«M(g«>
Messafls
Command
10
Request data
1
Data
set
t
RQl
<HH)
DTI {12H)
s
Request data al
:
RQl
(11H)
This message
is
sent out
when
there
is
a
need
to acquire data
from
a device at the other
end
o( the interface,
it
contains data
for
the address
and size that specify designation and length, respectively,
of
data
re<iuircd.
On
receiving
an RQl
message, the remote device checks
its
memory
for
the data address
and
size thai
satisfy the rcquesl.
If it
finds
them and
is ready for
communication, the device win
transmit
a
"Data
set
1
(DTt)" message, which
contains the requested
daia.
Oihcrwise, the device
will
send out nothing.
6vt8 Oescfiption
POH
Exclusive stalus
41H Manufacturer
ID (Roland)
OEV
Oevice ID
MDL
Model ID
11H
Command
ID
aaH Address
MSB
LSB
SSH Sije
MSB
LSB
sum
Check
sum
F7H end
of exclusive