Siemens S7-1200 connection problem

[ertankucukoglu]

Hello,

Using Delphi 10.2 with 1.6.7 version of the library. I have Indy 10.6.2.5366 installed.

I am using Indy10 ModbusMaster demo application to test a connection and I constantly receive socket error 10061 connection refused.

I have installed Modbus Slave application of Witte Software in demo mode to make a test connection and that application can connect to PLC device just fine on same computer and apparently same settings.

Is there any known issues with siemens PLC devices?

Thanks.

[ertankucukoglu]

After working on the problem. It turns out that I need to set TIdModbusClient.BoundPort to 502 for connection to be established fine. However, when I do that, I start to receive Address already in use error messages if I am to close and open the demo application.