I recently downloaded OpenAPC for Windows x86 (my laptop's OS is Windows 7 Professional, 32bit) and I am getting familiar with Control Room's functions. I have been trying to get status of digital inputs and value of holding registers from a Siemens's PLC, which I programmed to work as a Modbus Server, and display the result to Control Room. But I could not succeed. I have been using some Modbus tool to check the performance of PLC and it is still working correctly (inputs and register of PLC give correct results to Modbus tool). 

So I would like to get help from experts of OpenAPC. Particularly I would like to have a simple example which can read status of Digital Input Register 1 and content of Holding Regster 40001 to Holding Register 40003.

 

Thanks in advance  Regards