Skip to content

"Incomplete message received" - Cannot read values of registers #421

@HAMH96

Description

@HAMH96

Versions

  • Python: 3.4.2
  • OS: Debian (Raspberry 3B)
  • Pymodbus: 2.2.0
  • Modbus Hardware (if used): Multifunction Energy Meter YG889E-9SY

Pymodbus Specific

  • Server: Serial - Sync
  • Client: RS485 - I don't know if sync or async
    I use a RS485 to USB converter connected to raspberry

Description

What were you trying, what has happened, what went wrong, and what did you expect?
Hi, I am trying to read the measured variables from the energy meter, using modbus and a python 3 code, I am able to do the connection, but when I ask for a value of a register it gives me an error:
Modbus Error: [Input/Output] Modbus Error: [Invalid Message] Incomplete message received, expected at least 2 bytes (0 received)

Code and Logs

from pymodbus.client.sync import ModbusSerialClient as ModbusClient
#from pymodbus.register_read_message import ReadInputRegisterResponse
#The line above is commented because it gives me an error saying that it is not able to import that

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(1,1)

#value = client.read_discrete_inputs(1,1)

#value = client.read_holding_registers(1,1)

#value = client.read_coils(1,1)

print(value)

The connection is done succesfully because it prints TRUE, but whatever read request I try gives me the same error. Also I tried with print(value.bits[0]) but it says that 'ModbusIOException' object has no attribute 'bits'. Please help, I am new in this.

Metadata

Metadata

Assignees

No one assigned

    Type

    No type

    Projects

    No projects

    Milestone

    No milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions