mihaiciprian17 posted a topic in FestoHello i'm new in all things about plc, i do a project for school and i use a festo fc 34 plc. The plc is programmed via serial port RS232 my pc not support a serial interface and i use a RS232 to usb adapter. when a try to download the program to plc give me a error: "ERROR: Cannot access controller". What i do wrong. Thank you in advance and sorry for my English. Have a nice day.