Roland M-400 - Setup; About the RS-232 C Interface; Connector and Cable; Handshaking

5
Setup
RS-232C is a standard serial interface. An explanation of the connections used by the M-400 is given below.
When data is sent from the computer and the M-400’s processing speed is slower than the speed of the
incoming data, something must be done to prevent part of the data from being lost. Conversely, when data is
transmitted from the M-400 and the computer’s processing speed is slower than the arriving data, loss of data
can occur in the same way.
For this reason, the M-400 uses “Xon/Xoff” handshaking. The external computer can control the transmission
from the M-400 in the same way.
“Xon”: This signal is named DC1 (11H) in ASCII code; it is a control code requesting that transmission be started.
“Xoff”: This signal is named DC3 (13H) in ASCII code; it is a control code requesting that transmission be stopped.
About the RS-232C interface
Connector and cable
Handshaking
7
968
123 54
Connector specifications
Pin number Signal name
1
2
3
4
5
6
7
8
9
NC
RxD (Data In)
TxD (Data Out)
NC
GND
NC
Connected to pin 8
Connected to pin 7
NC
*1 Connected internally within the M-400 (pins 7 and 8).
*2 In order for the M-400 to operate, the three pins RXD, TXD,
and GND must be connected as shown in the diagram.
Cable specifications
RS-232C CABLE
*2
M-400 COMPUTER
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
FG
RxD
TxD
GND
*1