Answer: Please see the following examples:
Example about PIN and PUK:
AT+CLCK=“SC”,1,“0000”,1 ---->When you want to set pin code “0000”
OK
–Reboot module
AT+CPIN?
+CPIN: SIM PIN
OK
AT+CPIN=“0000”
OK
AT+CPWD=“SC”,“0000”,“1234” ---->When you want to change the pin code to “1234”
OK
–Reboot module
AT+CPIN?
+CPIN: SIM PIN
OK
AT*PSPRAS?
PSPRAS: 3,10,255,255
OK
AT+CPIN=“7777” ---->Input the wrong pin code will reduce the available try times
+CME ERROR: incorrect password
ATPSPRAS?
*PSPRAS: 2,10,255,255
OK
AT+CPIN=“1234”
OK
AT+CPIN?
+CPIN: SIM PUK
OK
AT+CPIN=“44753796”,“1234” ---->When you want to input the PUK code after you input 3 times of the wrong pin.
OK
AT example to remove the PIN code:
AT+CPIN?
+CPIN: SIM PIN
OK
AT+CPIN=“1234”
OK
AT+CLCK=“SC”,0,“1234”,1
OK