I am trying to let CMU200 recognize MC8975V. The initialization AT commands I sent to modem is “AT+CFUN=1” which turns full functionality on. After this I was trying to use “ATD”, “ATA”…etc commands.
This seems to work on normal activated AT&T SIM card but CMU200 test sim card. Is there anything that I missed to initialize the SIM card?
Thanks for your help
What is the difference between normal AT&T sim card and your test sim card?
Maybe you dont check pin code of test sim card. Try evaluating AT+CPIN? response. Also you can check AT+CREG command response to be sure of gsm connection.
And Which error code or response do you get when you use ATD with test sim card?