HL8548 respond error when enter SIM PIN

Dear all,

I have problem when using HL8548 with PIN SIM. My SIM require password after reboot module. When i enter command AT+CPIN=“1234”. Sometimes it respond OK but almost it respond CME Error: Operation is not allowed. And i don’t know how do next.

Could you please give me some advice to handle that problem.

Thank in advance!

The following syntactical definitions apply: Carriage return character, is the command line and result code terminator character, which value, in decimal ASCII between 0 and 255,is specified within parameter S3. The default value is 13. Linefeed character, is the character recognised as line feed character.