I want to get string from only the USB bar code scanner ,I try with assignment in operator mode and request_string_from_primary_client("") but it will show the keyboard on the robot screen and need to press the blank to show the cursor before use the bar code scanner.

Actually I try with CB2 robot and it work without touching on robot screen it's also show on screen keyboard but I just scan and the variable got the code number.
but when I use CB3 robot it doesn't work in the same way.
Are there any way to use USB scanner without on screen keyboard.