Are you running TLServer to connect to the PLC? The default settings after installation of TLServer and TRiLOGI software is 38,400, 8 data bit, 1 stop bit, no parity and you shouldn't need to change it. However, it is likely that you are not using the correct com port number. Does your PC has a built-in COM port? If so, then the COM port number is typically COM1 or COM2. But if it is a USB to RS232 converter then the COM port could be COM4,5,6,7 etc. Please try a different COM port number to see if you can get it to work.