InputScript Barcode scanner: I have added an InputField on a screen that is filled using a barcode scanner. How can I now start an InputScript as soon as this field is filled by the scanner?

The barcode scanner can add a "<Return>" after inserting the scanned code (configurable in the scanner, e.g. set a suffix after scanned digits).  In your InputScript use

On Enter process="..."

to start your script with the "Enter". Then check if the barcode entry field has changed. Example:

// GuiXT script

Set V[barcode1] "&V[barcode]"

// InputScript

...

if not V[barcode=&V[barcode1]]

...

endif