Panasonic KX-TD500 System Reference Manual page 1342

--Operation Chart--
<STATUS 1>
Note : In any status, pressing the END key restores <STATUS 1>.
PITS station program-
ming mode
PITS PGM No?
Dial "0 3"
• Port number (physical
number) & DN appears on
the display.
• The MEMORY button
indicator light goes out.
13-C-30