i read all the comments in this forum about unpassword of S7-200.
Recently, i can unpassword the S7-200 CPU224 DC/DC/DC, everything was fine.
i can get the password from the S7-200 utilities which i download from this forum.
Anyway, there is a PLC S7-200 CPU224XP. I try with same setting; PC/PPI RS232/RS485 cable link, usb-to-serial.
However, every utilities cannot online to the PLC. But if I online by using MicroWin, it can online.
My work is just backup the plc program from old plc to the new one but it is password protected
Thank you