Looked up "scan tags", didn't find anything. Can you clarify?
[1] https://cdn.sparkfun.com/assets/b/5/0/e/e/DY_Scan_Setting_Ma...
... but yeah, it should require pressing a recessed button with a pin or something. not allow it all the time.
That's rare though, and sometimes the installer disables it for convenience while they're debugging the system and never re-enables it. So the vast majority of scanners in the wild will happily accept an enter-config-mode at any time.
https://downloads.dell.com/manuals/all-products/esuprt_tab_m...