Roland Exclusive Messages
=
Request data : ROD (41
H)
This message is sent out
when
there is 3 ned to acquire data
from a
device
at (he other end of the interface. It contains data
for the address and size that specify
designation and length,
respectively, of data re<)uircd.
On receiving an RQD message, the remote
device
checks its
memory (or the data address and size
which satisfy the request.
It it finds them
and is
ready for
communication, the device will
transmit a "Data set (DAT)' message,
which
contains (he
requested data. Otherwise, it
will
return a "Rejection (RJC)"
message.
Byie Oesc
riot ion
FOH
Exclusive
status
41H
Manufacturer ID (Roland)
oev Device ID
MOL Model
ID
41H
Command ID
agH
Address MSB
LS5
SSH Size
MSB
LSS
sum Check sum
F7H End of exctusivs
*Thc size of the requested data does
not indicate the numtwr
of
liytcs that make
up a
'Data set (DAT)' message, t)ut
represents the address fields where (tic requested data
rcsides-
ixSome
models arc subject to limitations in data format used
for 3 sinitle transaction. Requested data,
for example, may
have
a limit in length or
must
be
divided into predetermined
address fields Ixtforc it
is
exchanged across (he interface.
*Thc
same number of bytes comprises address and size daia.
which. hoivc\'er,
vary wiih
the
Model
ID.
*The error
checking process uses a checksum that provides
a bit patiem where (he least significant
7
bits arc zero
when
values
for an address,
site, and that cheeKsum are summed.
:
Data set : OAT
(42H)
1'his message corresponds to the actual daia transfer
process.
Because every byte in (t>e data is
assigned
a
unique address,
the message can
convey the starting address of one or more
data as
well
as a
series of data formatted in an address-
dependent order.
Aiihou»{b the .MIDI standards inhibit non-real time messages
from
interrupting an
exclusive
one, some
devices support
a
"sofi'ihrouKh"
mechanism for such interrupts. To
maintain
compatibility with such
devices,
Roland has limited
the D.'\T to
256 bytes so that an
excessively long message is sent out in
separate scRmcnis.
Byte
Description
FOH
Exclusive
status
4IH Manufacturer
ID (Roland)
DEV
Device 10
MDL
Model ID
42H Command
iD
aaH
Address MSB
LSB
dOH Data
sum
Check sum
F7H
End of exclusive
*.\
DAT
message is capable of
providing only the valid
data
among those specified by an RQD or
WSD message.
«Some models are subject to
timi(3(ions in data format used
tor a
single transaction. Requested data, for example, may
have a
limil in length
or
must be
divided
into
predetermined
address fields before it is exchanged acn^ss
the interface.
•
The
number of bytes comprising address data
varies from
one
model ID
to
another.
«Thc
error checking process uses a checksum that
provides
a
bit pattern
where the least significant
7
bits
arc
zero
ivhen
valties tor
an address, size, and that checksum
are summed.
: Acknowledge: ACK clSH)
This message is sent
out
when
rto error was
delected un
reception of a WSa DAT, "End
of data (EOD)', or some other
message and a requested setup or
aciitwi is conmletc. Unless
ii receives an
ACK
message,
the
device
at the other end «in
not proceed to the next operation.
Byte Dsscrip lion
FOH
Exclusive status
4IK
Manufacturer
ID
(Roland)
DEV Oeviea ID
MDL Model ID
43H Command ID
F7H End of exclusive
= End of data EOD (45H)
This
message
is sent out to inform
a
remote device of
the end
ot a message,
(iimmunicatioo, however, will
not tome lo an
end unless the remote
device
returns an .\CK IUL^^41W evi-n
though an EOD message was transmitted.
Byte
Description
FOH Exclusive status
41
H
Manufacturer ID (Roland)
DEV Device ID
MDL Model
ID
4SH Command 10
F7H
End
ot exclusive
:
Communications error : ERR (4EH)
1'his message
warns
the remote device ut a Lummunica
lions
fault encountered during
message
transmission
due.
f<ir
example, to a checksum error. An UUlt message
may
lie
replaced
wiih
a "Rejection (WO" one.
which
icrminaics the
current message transaction in midsircam.
When
it
receives
an ERR message, (he senilinc device ma>-
either
attempt to send out the last messaKO a second time or
terminate
communication by sending out
an
\i)C nK-f^in.:
Byco Description
FOH Exclusive
status
41H
Manufacturer ID
(Roiand)
DEV
Device 10
MDl. Model ID
4EH Command ID
F7H End of exclusive
:
Rejection : RJC
(4FH)
This message is sent out when there is
a need
lo terminate
communication by
overriding
the current
ntcM^xe.
An iiJC
message
win
be triggered
when
;
• a
WSD
or RQD
message has spccifiiil
an
iJJcKjl
data
addiv.v.
or size.
• the
dev'ice is not ready for
(.'i)inniiiiii(jLl«n.
•
an illegal number of addresses
or
datu has
i>ocn
deiecuil.
• data
(ransfer has been
terminated liy
on niuraKir,
• a communications
error has occurrwl.
An ERR message may
be sent out by a deviui: iin either side
of the interface.
Communicatinn must
\k
tcrniiiiuii.il
immediately
when cither side irisKcrs an liKIi luessaw.
Byte
Oescription
FOH Exclusive
status
41
H
Manufacturer
ID (Roland)
DEV
Device 10
MDL
Model ID
4FH Command
10
F7H End of
exclusive
118
To Next Page
Loading...
Need help?
General
