Could someone help me to fix this error while trying to connect RPi 3 B+ to an inverter in order to read data via CH340G usb module, Below the used code :
from pymodbus.client.sync import ModbusSerialClient as ModbusClient
from pymodbus.register_read_message import ReadInputRegistersResponse
client = ModbusClient(method='rtu', port='/dev/ttyUSB0', stopbits=1, bytesize=8, parity='N', baudrate=9600, timeout=0.3)
connection=client.connect()
print(connection)
value=client.read_input_registers(2301, 4, unit=0x01)
print(value.registers)
Error message:
Traceback (most recent call last): File "/home/iot/Desktop/test.py", line 6, in value=client.read_input_registers(2301, 8, unit=0x01) File "/usr/local/lib/python3.6/dist-packages/pymodbus/client/common.py", line 125, in read_input_registers – return self.execute(request)
File "/usr/local/lib/python3.6/dist-packages/pymodbus/client/sync.py", line 105, in execute raise ConnectionException("Failed to connect[%s]" % (self.str())) pymodbus.exceptions.ConnectionException: Modbus Error: [Connection] Failed to connect[ModbusSerialClient(rtu baud[9600])]
