Hi,I’m using an arm board and SIM7100E. It is executing AT instructions. First, according to the handbook, when I open ports, the modem configuration should look like the one in the figure below, but in my case, it doesn’t.
Using AT+CPIN does not work to detect the sim, although there may be a hardware problem. The error message that appears when I type AT+COPS=? indicates that this command is not supported. The manual states that if AT+CFUN=0, SIM services would be terminated. Every time I enter AT+CFUN=1,1 it resets, and then it returns to AT+CFUN=0. When I enter AT+CFUN=1,0, it returns Operation Not Supported.
Because the voltage that the gsm through VBAT is receiving is 3.36 volts, I’m not sure if the problem is a hardware issue or a firmware one right now?. Any assistance would be greatly appreciated. 
