I'm having issues trying to connect to my controller via RS232, I can connect with can no problems however when I try with RS232 in both downloader and maintenance tool It can't connect.

I've checked the wiring and its all correct I have pin (wire 25 to pin 2 and wire 43 to pin3 and pin 5 grounded).

Is there something that would cause the serial port not to allow the system to establish communication? Is there any other way to set the system back to factory settings without RS232?