Serial port command operating on WIZ752SR-125


I am using WIZ752SR-125 and need to configure WIZ752SR throught RS232 port. I’ve enabled Serial command mode check box in Windows config tool and set Trigger code to 2B 2B 2B. Then I’ve connected RS232 cable (com-0-com) from my desktop to RS232-1 on WIZ board. I send and recieve messages beetwen tcp and RS232 througth configured port. But nothing happens when I try send command for switching port from data mode to command mode.
According command manual from Wizwiki my actions are:
I send SS+++\r\n, by serial port terminal.
Then I try to send SS\r\n or LI\r\n, but there is no effect. Requests apear on socket side and board does not answer.

May be I do something incorrect?