AT+CREG? Response empty

[Aleksander Morgado]

Hey,

> I have encountered an issue using ModemManager 1.16.8 via dbus.
> In my case there is a need to send periodic AT commands to a Cinterion modem to get infos about connection.
> For example AT^SMONI is ok and the response is not empty. However I would like to get also the response from AT+CREG?. But the response comes back empty. If I start the ModemManager in debug mode the output of the +CREG? can be seen in the debug window in the form:
> <-- '<CR><LF>+CREG:
> 2,1, and so on
> Which implies that the response of +CREG? on dbus is probably not parsed correctly. However I am not familiar with the ModemManager internals and would kindly ask if someone can clarify this?
>
> P.S. I can confirm the same behavior for version 1.15.0 too
>

This is a known and existing limitation of the Command() API in DBus.
The response to the CREG? query is parsed by ModemManager as a URC,
and it's "consumed" by the daemon itself, so the returned response
ends up empty.

-- 
Aleksander
https://aleksander.es