Modbus RTU

[BLL]

Hi, I need to read /write a device (EpSolar Tracer solar controller) which uses the Modbus RTU protocol. I have never used Modbus before.
Are there any libraries or tutorials already available to help?
I have read up on the protocol but can't as yet get my device to say anything!

Brian

[molly]

perhaps PascalSCADA is able to help you out there ?

[tr_escape]

Have you got  modbus address list of this device?

As Molly mentioned pascalscada has got modbus driver you can read and write to device if supports.

[BLL]

Hi all, Thanks for the replies.
Yes, I have  downloaded the manufacturer's specification, which has all the commands for reading/writing the device.
I will look at pascalscada, which I don't know at all.
Thanks
Brian

[avra]

Using PascalSCADA is nice, but might be an overkill if your needs are simple. For such cases you might want to just use mbutils lib:
http://forum.lazarus.freepascal.org/index.php?topic=11131.0

it is much better if you first establish a successful communication with your device using some modbus client like this free one: http://www.modbusdriver.com/modpoll.html

p.s. There is a search in forum, you know...

[sadikacar60]

friends pascal scada with plc say qp0 relay want to set. How can I do with pascalscada easily with the delphimodbus component.

Yours truly

Code: Pascal  [Select][+][-]

1. procedure TForm1.Button3Click(Sender: TObject);
2. begin
3.   TCP_UDPPort1.Host:='169.254.230.191';
4.   TCP_UDPPort1.Port:=502;
5.   TCP_UDPPort1.WriteState(???);
6. end;

windows also made with delphi modbus component

Code: Pascal  [Select][+][-]

1. procedure TForm1.Button1Click(Sender: TObject);
2. begin
3.     IdModBusClient1.Host := '169.254.230.191';
4.   if IdModBusClient1.WriteRegister(1, 1) then   //register-deger  1-0
5.   else
6.     MessageDlg('PLC register write failed!', mtError, [mbOk], 0);
7. end;

 

[mig-31]

It's so easy.
Look in PascalScada component examples directory and you can do it.