Try Using a null modem serial cable or adapter, pins 2 and 3 on one end of the DB9 connector need to be reversed.
Standard RS232 Pin for Pin Cable.
Null Modem Rs232 Cable with pins 2, 3 reversed.
- RS232 Null Modem Cable.png (1.04 KiB) Viewed 6876 times
Very Important....! In the setup menu, you must select the correct RS232 port for communication and have the RS232 port enabled, see the screenshot below. Also make sure your communicaions settings are correct, baud rate, etc.. Once the correct RS232 port is selected and enabled then the log will show all the data for external RS232 control.