Panasonic KX-TD500 System Reference Manual page 1385

2) After the diagnosis ends, "Complete" appears and waits for the
Displayed Message
entry of the next command.
OPR Test start
***** *****
F1 F2
01 02 03
L1
04 05 06
07 08 09
HLD MSG SPL PAG
10
11 12
Complete
******* *******
DIG >
(1) (2) (3)
Displayed Message
Error: Illegal main command
*****
Error: Illegal sub command
*****
F3 F4 F5 F6
L2 L3 L4 L5 L6
ANSWER
(4) (5)
There is an error in the main command.
There is an error in the sub command.
14-B-7
ATT-FWD PROGRAM
OFF ON OFF ON
F7 F8
ALM NIG
1 2 3
4 5 6
CANCEL
7 8 9
RELEASE
0 #
*
(6) (7) (8)
CTRL-C
Meaning