Panasonic KX-TD500 System Reference Manual page 1382

7) After the diagnosis of the display ends, the following display
Note :
Displayed Message
appears and waits for command entry.
DIG> DSP
DSP Test start
*****
Complete
*****
DIG>
(1) (2)
DSP LED OPR
( ) ( )
C C
R R
Pressing the F8 key or CRTL + C key during the diagnosis stops
the diagnosis and displays "Abort".
Displayed Message
Error: Illegal main command
*****
Error: Illegal sub command
*****
(3) (4) (5)
KEY REP
( ) ( ) (
C C C
R R R
There is an error in the main command.
There is an error in the sub command.
14-B-4
(6) (7)
ALL HELP END
) ( ) ( )
C C
R R
Meaning
(8)
( )
C
R