Mitel 5603 用户手册

The handset can be protected for unauthorized use. If this function is activated, a PIN code 
has to be entered at power on, or when the handset is placed in a charger - this behaviour will 
first be activated when the handset is placed in the charger. The default phone lock code (0000) 
can be changed to any 4-8 digit personalized code.

Select “Locks”.

Select “Auto phone lock”.

Select “On”, or "On in charger".

Enter a PIN code.

Press "OK". 

If the PIN code is forgotten it can be removed by your distributor.

Select “Locks”. 

Select “Auto phone lock”.

Select “Off”.

Enter a PIN code.

Press "OK". 

Select "Change PIN code".

Enter the old PIN code.

Press "OK".

Enter new PIN code twice.

Press "Save".

Answering

The default setting for the handset is to use the Off-hook key when answering a call. The 
answering behaviour can be configured to answer the call automatically, i.e. without pressing 
a key, and/or in loudspeaking mode. you can to set the answering behaviour to any key. If "Any 
key" is selected, any keys except the "On-hook" key and the "Sound off" key can be used to 
answer a call.

Note: If configured in the PDM/Device Manager, any of the predefined emergency 
numbers can be called while the handset is locked. See the Mitel 5603 Wireless Handset 
Configuration Guide.