I’m evaluating the EM7511 for its SMS capabilities and have run into a problem. The modem sends PDU SMS messages just fine, but I’m having trouble getting it to receive SMS in PDU mode.
Here’s the problem:
- New SMS notifications arrive as unsolicited messages of the form: $QCMTI: … (undocumented)
- They should be arriving as: +CMTI: … (documented)
- Reading these messages with the standard AT+CMGR FAILS. They are not stored in storage as defined by AT+CPMS (AT+CMGL shows an empty list). Where are these messages?
- Apparently, there are a number of undocumented commands that start with AT$Q… So extrapolating from that, reading these messages with AT$QCMGR does WORK. However, they are ALWAYS in text mode.
- The problem is: AT$QCMFG=0 FAILS. It does not support PDU mode, only text.
Why are there so many apparently undocumented commands for SMS receiving on this modem, which you are forced to use to receive messages? Am I missing the documentation for these somewhere?
How can this modem receive PDU SMS messages, which is necessary for concatenation, for example? This appears to be impossible from my testing with the undocumented commands.
I’m on the latest Verizon firmware in the US.