Hardware User Manual
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Copyright © 3onedata Co., Ltd.
4.2 TTL UART Port
This module has 2 TTL UART ports which could be configured to RS-232,
RS-485/422 and other communication modes. Each communication mode has given
reference circuit and description information, so user can configure communication
mode based on the requirement.
Pin Name
Type
Configuration Method
UART_RX[1:2]
Input
UART1-2 Received signal
UART_TX[1:2]
Output
UART1-2 Transmitted signal
UART_CTS[1:2]
Input
UART1-2 Clear to Send signal
UART_RTS[1:2]
Output
UART1-2 Request to Send signal
UART_DSR[1:2]
Input
UART1-2 Data Send Ready signal
UART_DTR[1:2]
Output
UART1-2 Data Terminal Ready signal
U_DCD[1:2]
Input
UART1-2 Data Carrier Detect signal
Reference Circuit for RS-232
Reference Circuit for RS-485 (Two-wire System)
The connection method of RS-485 two-wire system adopts half-duplex
communication method; its bus type topology structure enables it to connect up to 32
nodes on one bus. It usually adopts master-slave communication mode in RS-485
communication network, which is one master with multiple slaves. RS-485 transmits
signal in differential mode.
