On the BG95 mPCIe connected via USB, How can use the Modem port for a data connection while still having access to the AT port for commands?
You can use AT Port for AT commands. cannot do the PPP and AT commands same time on modem port.
You can pause the data connection and switch the port to AT command mode. Then later switch it back from command mode to data mode.
The switch requires the use of a guard time. This is a period of data silence, usually with a minimum value of one or two seconds.
The sequence to switch the port to command mode is:
<guard time>+++<guard time>
The AT command to switch from command mode back to data mode is ATO (that’s the letter “O”).
All modems recognise this mechanism. It’s use long pre-dates cellular modems.