Modbus slave

[MTZOVARAS]

Hi,

i am trying to develop a modbus slave, but i think i am doing something wrong
i have only nrSocket and nrModbus
i get the error you can see at c1
and another time i get 0000 values as a reply at C2
As i can see Modbus reply does not fire

What do you think ?

[MTZOVARAS]

Hello Roman,

do you need any other details about my problem ?

[MTZOVARAS]

Hello Roman,

is there a solution from you or should i do something from my side ?

i have a problem with this Modbus Slave !

i have to finish the software as soon as possible !

[Roman Novgorodov]

Hello

Sorry, we have problem with spam attack therefore some troubles with missed messages.
Please send to me ZIP archive with source code of test project and we will check.

Roman Novgorodov
DeepSoftware

[MTZOVARAS]

attached you can find my code for modbus slave

[Roman Novgorodov]

Hello

We bit modified your project: add button for renew connection awaiting and add logging.

I tested register reading from our ModbusDemo demo from virtual machine over TCP connection.
It works.

You cannot see attachments on this board.

Modified project:
You cannot see attachments on this board.

Please show me tool that you using for send request to slave.

Roman Novgorodov

[MTZOVARAS]

hello,

as i can see at my demo and your demo
line
listbox1.items.add('-------------------- in modbus reply');
never executes

see attached

reply with Exception Code : 2

[Roman Novgorodov]

Hello

The TnrModbus.ModbusReply event raises after reply from slave device.
It is not actual if TnrModbus component is in Slave mode it self.

Roman Novgorodov

[MTZOVARAS]

Hello,

can you please check tcp coil operation ?

i write 2 coils one with true, one with false,
but always read false

Thank you

[Roman Novgorodov]

Hello

Do use the ModbusDemo or your own code?

Roman Novgorodov

[MTZOVARAS]

Hello,

i have a device that acts as a Modbus Master and my software acts as Modbus Slave
The device asks my software about some register values and some coil values
Then the device wants to write to some other registers of my software via function 6 and 16
What i have to do at my software to take the values of these registers ?

Thanks

[Roman Novgorodov]

Hello Τζοβάρας,


Thank you for information.
 
It seems like you are right. We reproduced problem. Event ModbusRequest receives correct value but component returns not correct value or lost value.
 
procedure TForm1.nrModbus1ModbusRequest(sender: TObject; Reply: TnrModbusPacket;
  Registers: TnrModbusRegisterList; Coils: TnrModbusCoilList; isWrite: Boolean;
  var error_code: TnrModbusError);
var  sCoil : string;
    i:integer;
begin
  sCoil := '';
  for I := 0 to Coils.Count - 1 do
  begin
  sCoil := sCoil + 'Device: ' + IntToStr(Reply.Address) + ' Coil:' + IntToStr(Coils.GetCoilNumber(i)) + ' = ' + IntToHex(Coils.GetCoilValue(i).ToInteger(), 4) + #13#10;
  // listbox1.items.add('in modbus request : '+sreg);
  end;
  mmoErrorLog.Lines.Add(sCoil);
end;
 
 
I hope we will fix this problem at Monday.
 


Roman Novgorodov

DeepSoftware llc

[Roman Novgorodov]

Hello

Please try new version v9.70

Roman Novgorodov

[MTZOVARAS]

Hello,

i have a device that acts as a Modbus Master and my software acts as Modbus Slave
The device asks my software about some register values and some coil values
Then the device wants to write to some other registers of my software via function 6 and 16
What i have to do at my software to take the values of these registers ?

Thanks

[Roman Novgorodov]

Hello

Yes of course, TnrModbus component provides the following methods:

Code Select Expand

   
    procedure WriteRegister(const reg, val : word); overload;
    procedure WriteRegister(const reg, val : word; const addr: byte); overload;
    procedure WriteRegisters(const reg: word; values: array of word); overload;
    procedure WriteRegisters(const reg: word; values: array of word; addr:byte); overload;

For single and multiply regs writing.

Roman Novgorodov