Roland MT-32 - Page 35

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Rejection
:
RJC
(4FH)
This
message
is sen! qui
when ihcre
is a need to
terminate
communicaiion Ijy overriding Ihc current message. An RJC
message will
be
[riggercd when :
a WSD or ROD message has
specified an illegal dala address
or
size, or the device is not
ready for communication.
an illegal number of addresses
or data has been detected.
data transfer has been
terminated by an
operator.
a communications
error has
occurred.
An ERR message may
be sen!
out
by
a device
on
either side
of
the interface .
Communication
must be
terminated
immediately when
cither side triggers an ERR message.
Byte
Description
FOH
Exclusive status
41H Manufactures
10 (Roland)
DEV
Device
ID
MDL
Model ID
4FH
Command
ID
F7H
End of exclusive
#
Example of Message
Transactions
•
Data transfer from
device (A) to device
(B).
Device (A)
Device
(B)
{Want to send data]
{Data set]
[Data
set)
{End of
data]
iaj
—
—
(Acknowledge]
[Acknowledge]
[Acknowledge]
[Acknowledge]
•
Error occurs
while device (A)
is receiving data
from
device
(8).
I) Data transfer
from device (A) to
device
<B).
Device
(A)
Device (B)
[Acknowledge]
(Error)
x —
t-
(Communication
error]
[Data set]
[Data set]
[Data set]
[Acknowledge]
(the same data
*"
as
above)
2)
Oevice
(B)
rejects
the
data
re-transmitied,
and
completes
data
transfer.
Device (A)
Device (B)
[Acknowledge]
(Error)
x
-mi
—
[Communication error
}-
(Complete) *
[Data set]
[Data
set]
[Rejection]
3)
Device
(A) immediately
completes
data
transfer.
Device (A)
Device (B)
[Acknowledge]
(Error)
x
[Rejection]
[Data
set)
[Data set]
*-
(Complete)
i Device (A) requests and
receives data from device
(B).
Device
(A)
[Request data)
[Acknowledge]
[Acknowledge]
[Acknowledge]
Device (B)
[Data set]
[Data set]
[End of
data]