关键发送代码：通过b开头，把\x格式的16进制发送到串口
NoOfBytes = COM_Port.write(b'\xFE\x05\x00\x00\xFF\x00\x98\x35')
或用下面代码发送HEX: 和上面的b'xxxxx'一样 ，这个data变量应该都是bytearray格式的
data = ('FE0F000000080100B191').decode('hex') # Write data to serial
NoOfBytes = COM_Port.write(data) # Write data to serial port
华为ar502h 的232串口为/dev/ttyO0 ,
485串口为/dev/ttyO1，
详细测试代码如下：
#----------------------------------------------------------------------------------------------------# # RS485 Communication using Python (Write) (hardware = USB2SERIAL) (Python 2.7.x) # #----------------------------------------------------------------------------------------------------# #Program runs on the PC side and transmits a character to the Serial Port @9600bps .Program uses # #PySerial module to communicate with Serial Port of USB2SERIAL # #----------------------------------------------------------------------------------------------------# # BaudRate -> 9600 # # Data formt -> 8 databits,No parity,1 Stop bit (8N1) # # Flow Control -> None # #----------------------------------------------------------------------------------------------------# #====================================================================================================# # www.xanthium.in # # Copyright (C) 2015 Rahul.S # #====================================================================================================# #====================================================================================================# # Interpreter/IDE : Python 2.7.x/IDLE # # Module : PySerial # # # OS : Windows(Windows 7)/Linux # # Programmer : Rahul.S # # Date : 31-March-2015 # #====================================================================================================# #====================================================================================================# # Finding out the serial port number corresponding to your Computer # #====================================================================================================# # On Linux # #----------------------------------------------------------------------------------------------------# # USB2SERIAL will be detected as ttyUSB0 or ttyUSB1.You can check the port number of USB2SERIAL by # # connecting you board to USB port and doing # # dmesg | tail # # and checking the output. # #====================================================================================================# #====================================================================================================# # Running the Program # #====================================================================================================# # On Linux # #----------------------------------------------------------------------------------------------------# # Find out your serial port name and number corresponding to USB2SERIAL on your system.It will be- # # -usually in the form of ttyUSB0 and ttyUSB1. # # Open terminal and type the following command to invoke Python3.x interpretor # # [user@linux:~$] sudo python RS485_Write.py # # Give the password and then enter your portnumber when program asks ->/dev/ttyUSB0 # #----------------------------------------------------------------------------------------------------# # On Windows # #----------------------------------------------------------------------------------------------------# # Open the command prompt and type the following # # C:\>python RS485_Write.py # # Enter the COM number when program asks -> com31 # #====================================================================================================# import serial # import the module def banner_top(): print ' +-------------------------------------------+' print ' | USB2SERIAL RS485 Write in Python 2.7.x |' print ' | (c) www.xanthium.in |' print ' +-------------------------------------------+' def Usage(): print ' | Windows -> COMxx eg COM32 |' print ' | Linux ->/dev/ttyS* eg /dev/ttyUSB0 |' print ' +-------------------------------------------+' def banner_bottom(): print ' +-------------------------------------------+' print ' | Press Any Key to Exit |' print ' +-------------------------------------------+' banner_top() # Display the top banner Usage() COM_PortName = raw_input('\n Enter the COM Port Name ->') #Opening the serial port COM_Port = serial.Serial(COM_PortName) # open the COM port print '\n ',COM_PortName,'Opened' COM_Port.baudrate = 9600 # set Baud rate COM_Port.bytesize = 8 # Number of data bits = 8 COM_Port.parity = 'N' # No parity COM_Port.stopbits = 1 # Number of Stop bits = 1 print '\n Baud rate = ',COM_Port.baudrate print ' Data bits = ',COM_Port.bytesize print ' Parity = ',COM_Port.parity print ' Stop bits = ',COM_Port.stopbits #Controlling DTR and RTS pins to put USB2SERIAL in transmit mode COM_Port.setDTR(0) #DTR=0,~DTR=1 so DE = 1,Transmit mode enabled COM_Port.setRTS(0) #RTS=0,~RTS=1 (In FT232 RTS and DTR pins are inverted) print '\n DTR = 0,~DTR = 1 so DE = 1,Transmit mode enabled' print ' RTS = 0,~RTS = 1' #Write character 'A' to serial port data = bytearray(b'A') # Convert Character to byte array NoOfBytes = COM_Port.write(b'\xFE\x05\x00\x00\xFF\x00\x98\x35') # Write data to serial port print '\n ',NoOfBytes,' bytes written' print '\n A written to',COM_PortName COM_Port.close() # Close the Serial port banner_bottom() # Display the bottom banner dummy = raw_input() # press any key to close