Are you your sure that the message code is correct for the respective mobile phone provider? Each provider has it's own unsolicited message codes, e.g. for balance check.
Are you your sure that the message code is correct for the respective mobile phone provider? Each provider has it's own unsolicited message codes, e.g. for balance check.
Yes,I'm sure. when I use this code (*140*11#) in the mobile phone,I will receive correct answer.
But I don't know that why answer by the module is incorrect.
I didn't notice the "unreadable characters" point. Problem is that some providers answer with an alphabet that enforces PDU mode. I remember that I needed to implement a PDU decoder to receive CUSD responses in a SMS application. Not sure if it might help to change the default alphabet.
I didn't notice the "unreadable characters" point. Problem is that some providers answer with an alphabet that enforces PDU mode. I remember that I needed to implement a PDU decoder to receive CUSD responses in a SMS application. Not sure if it might help to change the default alphabet.