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2026-01-13T02:08:44Z

Created page with " === '''HW Pin define：''' === === '''SW Function：''' === File:AFE-R761 CAN Number.jpg === '''Configure RS232 or RS485''' === ttyS3 and ttyS5 support only RS485..."

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=== '''HW Pin define：''' ===

=== '''SW Function：''' ===

[[File:AFE-R761 CAN Number.jpg]]

=== '''Configure RS232 or RS485''' ===

ttyS3 and ttyS5 support only RS485 mode, whereas ttyS6 and ttyS9 support configuration for both RS232 and RS485 modes. The default mode is RS232.

Set RS232 or RS485 separately(0 means RS232;1 means RS485):

'''Set ttyS6 to RS232 mode and ttyS9 to RS232 mode.'''
<pre># fw_setenv uart_mode_cpu 6:0,9:0
# reboot
</pre>

'''Set ttyS6 to RS232 mode and ttyS9 to RS485 mode.'''
<pre># fw_setenv uart_mode_cpu 6:0,9:1
# reboot</pre>

'''Set ttyS6 to RS485 mode and ttyS9 to RS232 mode.'''
<pre># fw_setenv uart_mode_cpu 6:1,9:0
# reboot
</pre>

'''Set ttyS6 to RS485 mode and ttyS9 to RS485 mode.'''
<pre># fw_setenv uart_mode_cpu 6:1,9:1
# reboot
</pre>

=== '''Configure Parameters''' ===

Use “stty” command to configure serial port parameters. The commonly used parameters include “Baud rate”, “Data bits”, “Stop bits”, “Parity”, “Flow control”.<br/> '''See details of the usage of “stty”:'''
<pre># stty --help
… …
csN set character size to N bits, N in [5..8]
[-]cstopb use two stop bits per character (one with '-')
[-]parenb generate parity bit in output and expect parity bit in input
[-]crtscts enable RTS/CTS handshaking

… …
</pre>

'''For example,'''

set COM4 "Baud rate" to 115200 “Data bits” to 8 “Stop bits” to 1 “Parity” to None “Flow control” to None.
<pre># stty -F /dev/ttyS3 115200 cs8 -parenb -cstopb -crtscts
</pre>

=== '''Send and Receive Data''' ===

'''Taking COM4 as receiver and COM2 as sender:'''
<pre># #---- COM4 as receiver ----# #
# stty -F /dev/ttyS3 115200 cs8 -cstopb -parenb -crtscts
# stty -F /dev/ttyS3 115200 cs8 -cstopb -parenb -crtscts

# stty -F /dev/ttyS3 115200 cs8 -cstopb -parenb -crtscts
# stty -F /dev/ttyS5 115200 cs8 -cstopb -parenb -crtscts
# echo pass > /dev/ttyS5

# #----If no error, the receiver will receive “pass”----# #
pass</pre>

[[File:AFE-R761 UART RM01.png]]

[[File:AFE-R761 UART RM02.png]]

AFE-R761 UART（COM1/2/3/4） - Revision history

Xingxing.li: Created page with " === '''HW Pin define：''' === === '''SW Function：''' === File:AFE-R761 CAN Number.jpg === '''Configure RS232 or RS485''' === ttyS3 and ttyS5 support only RS485..."