Modify the ETL chassis name by entering a new name in the Modify section and then select Modify to apply the changes.  The Input Port list items can be changed to meaningful names by changing the Port Name in the Modify section, and selecting "Modify"

Change the ETL port from the AVCOM GUI by selecting the ETL chassis in the "RF Switch List", then selecting the desired port from the "In" menu.  When the "In" menu selection changes, the GUI automatically tries to command the change.  The status LED (under the RUN button) will change to green if successful.  Selecting "Run" will manually initiate the change channel command and verify the change.

Here is a picture of a screen shot of the GUI showing the drop-down function to select the appropriate port.  These ports can be renamed for easy recognition and access.

Here is a picture of the RSA-2150C-16S-ETL GUI showing four signals at the same time.  The GUI can be configured to show 12 screen shots on one view!