If the panel is bleeping then there has to be some indication on it too.
Unless a jamming is detected but thats indicated, and its 5 bleeps at a time. Sorry thinking out loud.
Does pressing ¬ stop it?
Other than that, power it down wait a min and repower, put code in.
Just becareful, mains is present and can kill.
Just read the book myself, cannot see anything else to try.
Alarm
February 2011