Tips 01:

Windows data type and size are different in TwinCAT structured text. This causes problems, especially when we write data over ADS in C#. Here is an example, we have declared a variable in the Windows program as the following

int myWinInt = 200;

object rawValue = myWinInt ;

client.WriteAny(handle, rawValue); // This will throw an exception “parameter size not correct” if the variable in PLC is declared as INT type.

myPLCIntType : INT := 0; //Declared in PLC

Solution:

Make sure the data size in PLC is equal to or higher than the size of the Windows variable, the above case can be solved in the following way.

int myWinInt = 200;  // 4 bytes in Windows

myPLCIntType : DINT := 0; // 4 bytes in PLC

OR

short myWinInt = 200;  // 2 bytes in Windows

myPLCIntType : INT := 0; // 2 bytes in PLC