AT commands

[Dan Williams]

On Sat, 2015-09-26 at 01:11 +0200, Jean-Christian de Rivaz wrote:
> Le 25. 09. 15 20:35, Normand Roy a écrit :
> > I need to monitor modem temperature on modems running in a production environment. So running it in debug mode is not an option.
> >
> > I will make a suggestion to the modem manufacturer to implement a plug-in for MM. I won't be able to do this by myself.
> >
> > Thank you for your help.
> >
> >
> > -----Message d'origine-----
> > De : ModemManager-devel [mailto:modemmanager-devel-bounces at lists.freedesktop.org] De la part de Dan Williams
> > Envoyé : 25 septembre 2015 12:07
> > À : Highland, Glenn
> > Cc : modemmanager-devel at lists.freedesktop.org; Normand Roy
> > Objet : Re: AT commands
> >
> > On Fri, 2015-09-25 at 11:05 -0500, Dan Williams wrote:
> >> On Fri, 2015-09-25 at 15:44 +0000, Highland, Glenn wrote:
> >>> You need to run ModemManager in debug mode.
> >>>
> >>> From: ModemManager-devel
> >>> [mailto:modemmanager-devel-bounces at lists.freedesktop.org] On Behalf
> >>> Of Normand Roy
> >>> Sent: Friday, September 25, 2015 10:38 AM
> >>> To: modemmanager-devel at lists.freedesktop.org
> >>> Subject: AT commands
> >>>
> >>> Why is it not possible to send AT command to the modem while using the modem manager?
> >>>
> >>> I am using a Multi-Tech usb connected modem and I need to monitor
> >>> the temperature using
> >>>
> >>> AT#TEMPMON=1
> >>>
> >>> I did not found any way to send this command and get the result.
> >> To expand on this, ModemManager doesn't allow random AT commands in
> >> normal mode because (a) they can interfere with the ones MM is
> >> running, or cause unexpected replies that MM is not prepared for, and
> >> (b) MM tries to abstract modems and provide a consistent interface for
> >> many devices, and adding a path for custom commands just encourages
> >> people to do random custom stuff instead of working to make MM better.
> >>
> 
> Hi Normand,
> 
> As a user I don't want to make arguments about the politic of the 
> ModemManager project regarding your question, even if I strongly support 
> your request. But...
> 
> Pragmatically, many USB modems expose multiple serial ports. If it's the 
> case for your modem, there some chance that ModemManager don't use all 
> of them, leaving the possibility to use on unused USB serial port for 
> your own application, for example to query the temperature.

Yes, this is also a possibility.  You can see which ports MM is using by
asking it through the d-bus interface or with mmcli.  MM will list all
the ports its found, but will typically only use the data port and the
control port.

Dan