If you have two or more FLEX-6000s on the same IP network (subnet) they will all show up in the radio chooser.
If you want to force a specific PC to connect to a specific radio and this includes DAX and SmartSDR CAT too, there is a way to prevent other radios from connection to that particular PC.
The solution is to tell any SmartSDR programs that uses the API which radio to show up in the radio chooser by placing a file named filter.txt or filter in %appdata%\FlexRadio Systems directory.
You can create this file with Notepad, etc. and then save it to that directory.
The filter.txt file will need to contain full or partial serial number including the dashes of radio(s) that you want to connect to from the computer where you place the filter.txt file.
Generally, the file will contain one serial number on each computer. You can enter just the last 4 digits of the S/N since they are typically unique.
CAUTION: By default, Windows hides file name extensions. In addition, when creating a new text file on Windows, when entering the file name, Notepad will add the "txt" extension to to file name. If you entered the file name of filter.txt, you will end up with a file called filter.txt.txt but not know it because the file extension is hidden. So when creating a filter file for the FLEX-600, just enter a file name of filter.