RSB-4710 User Manual
42
3.4
UART
The Android/Linux UART/serial port access is via the tty-devices. The tty-devices
have different names depending on the UART driver on different boards.
RS-485 uses half-duplex communication, which means that one medium is shared
for transmitting and receiving data. Therefore the system needs to control the RS-
485 transceiver transmit mode. Usually the UART RTS signal is used to switch the
transmitter on and off.
3.4.1
RSB-4710 UART
3.4.2
How to Configure RS-232/485 Mode
Enter U-boot interrupt mode.
Connect the device to the debug port and open the debug console.
Press “ctrl + c” before powering on the device. The following information should be
displayed on the debug console:
Then input the following command to configure the UART mode.
RS-485 Mode:
RS-232 Mode:
Note:
The default value is RS-232.
Cp210x supports four ports, but for RSB-4710 only ttyUSB2 and ttyUSB3 support
RS-485 mode.
In the above command “setenv uart_mode 0x0c”, 0x0c means set bit2(ttyUSB2) and
bit3(ttyUSB3) to 1 (0 means to RS-232; 1 means to RS-485).
To configure just ttyUSB2 (or ttyUSB3) to RS-485 mode, change 0x0c to 0x04 (or
0x08).
COM Name
Device Node
Remark
COM1
/dev/ttyS4
Supports RS-232, no flow control
COM2
/dev/ttyS2
Debug port
COM3
/dev/ttyUSB0
Supports RS-232
COM4
/dev/ttyUSB1
Supports RS-232
COM5
/dev/ttyUSB2
Supports RS-232 and RS-485
COM6
/dev/ttyUSB3
Supports RS-232 and RS-485
Hit any key to stop autoboot: 0
=> <INTERRUPT>
=>
setenv uart_mode 0x0c
saveenv
reset
setenv uart_mode 0x00
saveenv
reset
Summary of Contents for RSB-4710
Page 1: ...User Manual RSB 4710 3 5 Single Board Computer with Rockchip Arm Cortex A72 Processor ...
Page 6: ...RSB 4710 User Manual vi ...
Page 15: ...7 RSB 4710 User Manual Chapter 2 Hardware Installation 2 2 Board Dimensions ...
Page 44: ...RSB 4710 User Manual 36 ...
Page 45: ...Chapter 3 3 Software Functionality This chapter details software functions on RSB 4710 ...
Page 56: ...RSB 4710 User Manual 48 4 Input the password 5 Wi Fi connected ...
Page 69: ...61 RSB 4710 User Manual Chapter 4 Advantech Services ...