Error in rading Input Register Error:No Response from Modbus Slave

[Arun Mahajan]

I have connected my Omron PLC with my laptop using a USB serial port converter. It gets connected successfully and I am able to read all values of port.

Now while I am trying to read the inputregistor it provides me the following error:

System.TimeoutException
HResult=0x80131505
Message=No Response from Modbus Slave
Source=EasyModbus
StackTrace:
at EasyModbus.ModbusClient.ReadHoldingRegisters(Int32 startingAddress, Int32 quantity)
at EasyModbus.ModbusClient.ReadHoldingRegisters(Int32 startingAddress, Int32 quantity)
at EasyModbus.ModbusClient.ReadHoldingRegisters(Int32 startingAddress, Int32 quantity)
at EasyModbus.ModbusClient.ReadHoldingRegisters(Int32 startingAddress, Int32 quantity)
at ConsoleTest.Program.Main(String[] args) in C:\Users\ARUMAH\source\repos\ConsoleTest\ConsoleTest\Program.cs:line 29

My C# program is like below:

EasyModbus.ModbusClient modbusClient = new EasyModbus.ModbusClient("Com4");

        modbusClient.Connect();
        //Console.WriteLine("available:" + modbusClient.Available(100));
        Console.WriteLine("connected:" + modbusClient.Connected);
        Console.WriteLine("IPAddress:" + modbusClient.IPAddress);
        Console.WriteLine("Port:" + modbusClient.Port);
        Console.WriteLine("SerialPort:" + modbusClient.SerialPort);
        Console.WriteLine("Baudrate:" + modbusClient.Baudrate);
        Console.WriteLine("Parity:" + modbusClient.Parity);
        Console.WriteLine("StopBits:" + modbusClient.StopBits);
        Console.WriteLine("UnitIdentifier:" + modbusClient.UnitIdentifier);
        Console.WriteLine("ConnectionTimeout:" + modbusClient.ConnectionTimeout);

          int[] readInpputRegisters = modbusClient.ReadInputRegisters(0, 4);

Could you please help me to sort out this problem.

Regards

[Anonymous]

I also have a similar issue. I am trying to read input registers, but have no idea how i shoud do it.
I am doing like this:

Console.WriteLine("Value of Input Reg #10: " + modbusClient.ReadInputRegisters(9, 1)[0].ToString());

But it is giving me the same error: No response from Modbus Slave.

[Rossmann Engineering]

I think the answer is pretty obvious, your Modbus Device is not anwering the request. (I think yo u did not forget to connect first?)

[Anonymous]