SeeedStudio EdgeBox-RPI-200 - Serial Port (RS232 and RS485)

EdgeBox-RPI-200 User Manual
WWW.SEEEDSTUDIO.COM 7
2.2.2 Serial Port (RS232 and RS485)
Pin#
Signal
Description
4
RS232_RX
RS232 receive line
6
RS232_TX
RS232 transmit line
8
GND
Ground (Reference potential)
Pin#
Signal
Description
3
RS485_A
RS485 difference line high
5
RS485_B
RS485 difference line low
7
RS485 _GND
RS485 Ground (isolated from GND)
The RS485_GND signal is isolated with “GND” signal. If a shielded twisted pair wire is used, the
RS485 _GND is connected to the shield.
NOTE: The 120 Ohm termination resistor for RS485 has been installed inside.