SMC Networks D-MH1AD Series Operation Manual page 52

If the security code function is enabled, it will be necessary to input a security code to release the key lock.
: If no key is pressed for 30 seconds or longer during security code entry, the product will return to function selection mode.
Changing the security code setting
Press the UP or DOWN button to enter the
required security code on the main display.
For instructions on how to enter a security
code, refer to "How to enter and change the
)
security code" (page 62
After entry, press the SET button for 1 second,
which causes the changed security code to
start flashing.
(At this point, changing of the security code is
not completed).
Press the UP or DOWN button to return to
setting step.
Press the SET button for
1 second to save the setting.
[F81] Setting of security code completed
-51-

.
Returns to function selection mode.
No.D-※S-OMA1021