This[1] reply on Twitter explains and includes a link and quote from the manufacturer’s manual for these signs, indicating the message will play if they have no

This[1] reply on Twitter explains and includes a link and quote from the manufacturer’s manual for these signs, indicating the message will play if they have not been set up properly (i.e., default out-of-the-box password still in place unchanged). This seems like the equivalent of the old blinking “12:00” on a VCR clock. [1] https://twitter.com/hyperplanes/status/1503275823360585735 https://twitter.com/hyperplanes/status/1503275823360585735