Hello dear!
EG8145V5 is not a manageable device using serial ports.
If you'd like to get the configuration file, follow the isntructions bellow:
In the navigation tree on the left, choose System Tools > Configuration File. In the pane on the right, click the button as required as shown in Figure 1.
Figure 1. Configuration File
Click Browse following the Configuration File text box. In the dialog box that is displayed, select the configuration file to be uploaded. Click Update Configuration File to upload the configuration file that is saved on the local disk. After the configuration file is successfully uploaded, the device automatically restarts and then the new configuration takes effect.