Roland U-20 Owner's Manual page 183

#
Rejection:
RJC
(4FH)
This mrasage
ts
sent out
when
there
is
a
need
to
terminate
communication by
overriding the current
message. An RJC
message
will
be
triggered
when
a
WSD
or
RQD
message
has
specified
an
illegal
data address
or
size.
the device
is
not ready
for communicatiwi.
an
illegal
number
of addresses
w
data
has been
detected.
data
transfer has been terminated by an i^rator.
a
communications
error
lias occurred.
An ERR
message may
be
sent out by a
devtra on
either side
of the
interface. Cmnmunication must be
terminated immediately
when
either side triggers an ERR
message.
Byto
EJasoHption
FOH
Exclusive
status
41H
MBniriacturor
ID CRoland)
DEV
Device
10
MDL
Model
ID
4FH
Command
ID
F7H
End
of exclusive
#
Example
of
Message
Transactions
•
Data
transfer from
device (A) to devloo
(BJ.
Device (A)
Device
CB)
[Want
to send data]
[Data
oat]
[Data
BBt]
[End
of data]
[Acknowladoe]
[Acknowledge]
[Acknowladoe]
[Acknowledge]
Error
occurs
while device (A)
is
rooeivino data from
devici
CB).
O
Data transfer from
device (A)
to device
(B).
Device (A)
Device
CB)
[Data
BBt]
[Acknowtedoe]
—
(Error)
x
-•-
[CommunioBtion
error]
'[Data
set]
[Acknowledge]
-
[Data
set]
(tlie
aame
data
-
as above)
2)
Da\rfce
(B) rejects the data
re
-
transmitied,
and
quits data
transfer.
Ot>\Ace (A)
Device
CB)
[Acknowledge]
___
(Error)
x .^
[Communication
error}-
(Quit)
-«—
[Deta
set]
[Dete set]
[Rejection]
3)
Device
(A)
immediataly
quits date
transfer.
Device (A)
Device
(B)
[Acknowledge]
(Error)
x
[Rejection]
[Data
set]
[Data
set]
-^
(Quit)
tDevice (A) requests and
receives data from
device
(B).
Device (A)
Device
(B)
[Request
data]
[Acknowledge]
[Acknowiedge]
[Acknowledfle]
^
m
^
[Data
set]
[Data
set]
[End
of data]