communication EST3 panel to fireworks

[khorasani]

Hi everybody,
I have 6 EST3 panels which are connected to each other through RS485 and one of these panels is connected to fireworks.Now I want to connect one of these panels to fireworks(using rs232 to usb convertor/please be noted that the rs232 to usb convertor is ok and I am using it for SDU configuration).
I have opend AUXPORT 2,GATEWAY III on 19200 buad rate, But I have connectivity problem, I have connected the pc with 5 meter length cable to panel following the installation manual.
and the rs232 card is installed on panel .
I still have AUXPORT2 TROUBLE on the LCD of Panel.
I have connected pin 2 to TX and pin3 to RX and and pin 5 to COM,in system builder I also set the comm port on gateway type 3 on 19.2K baud rate (It is just like as I set in SDU for cpu gateway,type III and 19.2K baud rate)
any one can help me please?
best regards.
Mehdi.