Roland RS 232C MP3 Player User Manual


 
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AR-3000 RS-232C Reference -3
Baud Rate Settings
Set the baud rate to the desired value. (Refer to owner's manual p.118)
1) Press the MODE button.
2) Rotate the SELECT knob to select “7.1 Baud rate.”
3) Press the SELECT knob.
4) Rotate the SELECT knob to select the baud rate.
Baud rate = 4800, 9600, 19200, 38400 bps
Select the same setting as on the computer.
5) Press the SELECT knob. Rotate the SELECT knob to select “Yes”
Press the ENTER button to set the baud rate.
6) Press the MODE button.
Section3 Overview of Commands
The AR-3000 and the computer communicate using commands.
3.1 Command Structure
Commands consist of STX (02H) + two uppercase characters.
However, the Type 0 commands listed later are exceptions to this.
3.1.1 Communication Protocol
Depending on the command, four types of communication protocol are used between the computer
and the AR-3000. As also explained in chapter 4, the ACK referred to in this document is ASCII
code 06H (ACK), and the ER command is a command that transmits/receives an error.
1) When telling the AR-3000 to perform an operation or make a setting.
This is done using the 4.2.1 Control and 4.2.3 Setting commands explained in chapter 4.
Commands use the following procedure.
a. stx + command
COMPUTER AR-3000
b. ack or stx ER command
a. The command is sent from the computer to the AR-3000.
b. If the command is received correctly, the AR-3000 will transmit an ACK command. If not, it
will transmit an ER command.
2) To verify the settings of the AR-3000
This is done using the 4.2.4 Request command explained in chapter 4. The command to check
the setting status of the AR-3000 uses the following procedure.
a. stx + command
COMPUTER AR-3000
b. ack or stx ER command
c. ack or stx ER command