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Roland HP 2700 - Address-mapped Data Transfer; Request Data Message (RQD); Data Set Message (DAT)

Roland HP 2700
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20
Roland
Exclusive
Messages
ff
data
Format
for
Exclusive
Messages
Roland's
MIDI
implementation
uses
the
following
data
format
for
alt
exclusive
messages
(type
IV):
FOH
Exclusive
status
41H
Manufacturer
ID
(Roland)
DEV
Device
ID
MDL
Model
ID
CMD
(BODY}
F7H
End
of
exclusive
Command
{D
Main
data
#
MIDI
status:
FOH,
F7H
An
exclusive
message
must
be
flanked
by
a
pair
of
slatus
codes,
starting
with
a
Manufacturer-ID
immediately
after
FOH
(MIDI
version1.0).
#Manufacturer|D:
41H
The
Manufacturer-ID
identifies
the
manufacturer
of
a
MIDI
instrument
that
triggers
an
exclusive
message.
Value
41H
represents
Roland's
Manufacturer-ID.
#Device-ID:
DEV
The
Device-ID
contains
a
unique
vaiue
that
identifies
the
individual
device
in
the
multiple
implementation
of
MIDI
instruments.
It
is
usually
set
to
OOH
~-
OFH,
a
value
smaller
by
one
than
that
of
a
basic
channel,
but
value
OOH
~
1FH
may
be
used
for
a
device
with
multiple
basic
channels.
#Model.lD:
MDL
The
ModeliD
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:
Ol
02H
03H
OOH,
01H
OOH,
02H
OOH,
OOH,
01H
+CommandID;
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
of
valid
Command-
IDs,
each
representing
a
unique
function
:
O1H
02H
03H
OOH,
01H
OOH,
02H
OOH,
OOH,
O1H
#
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.
yaa
Address.mapped
Data
Transfer
Address
mapping
is
a
technique
for
transferring
messages
conforming
to
the
data
format
given
in
Section
1. [t
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.
3
One-way
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
completely
independent
of
a
receiving
device
status,
Connection
Diagram
Device
(A)
Device
(B}
Connection
at
point
2
is
essential
for
“Request
data”
procedures.
(See
Section
3.)
xHandshake-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
reliability
and
transfer
speed
are
high
enough
to
handle
a
large
amount
of
data.
Connection
Diagram
Device
(A)
Device
(B)
Connection
at
points
{
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
ID,
and
are
ready
for
communication.
cas
One-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
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.
Types
of
Messages
RQ!
(11H)
DT1
(12H)
Request
data
1!
Data
set
|
#Request
data
+1:
RQ1
(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
tha!
specify
designation
and
length,
respectively,
of
dala
required.
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
(DT1)"
message,
which
contains
the
requested
dala.
Otherwise,
the
device
will
send
out
nothing.
Exclusive
status
Manufacturer
ID
(Roland)
Device
iD
Mode!
ID
Command
ID
Address
MSB
LSB
MSB
LSB
Check
sum
End
of
exclusive

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