Re: modems using same port for data & AT command

[Marcel Holtmann <marcel holtmann org>]

Hi Ran,

> > > I am using a device with one port for both data and connection (MC950D
> > > novatel), and it is interesting that after connecting with kppp I can see
> > in
> > > the kppp properties (after pressing "details" button) a window of "kppp
> > > statistics", which shows number of transmit/received packets. does it
> > mean
> > > that the kppp send AT command while in ppp connection ?
> >
> > the second port of the MC950D is by default in QCDM mode. You can send
> > AT$NWDMAT=1 to the first AT command channel and turn the second TTY also
> > into an AT command channel.
>
>  I did not find in the MC950D datasheet that it has any second port, which
> you said as being used for QCDM.
> Where did you read about it ?

don't remember, but my MC950D shows up with two TTY devices.

> > Network statistics are a different story - you're not querying the modem
> > for those; you're querying the ppp interface. The Linux kernel keeps track
> > of the network flowing over that interface. If you run 'ifconfig', you'll
> > likely see ppp0 as a network interface, complete with statistics.
> >
> >
> >
> If the statistics can be queried from the ppp interface, it gets me closer
> to the idea that AT commands are not used while in ppp connection, but I
> now see that this device (MC950D ) can send/recieved SMS message (which I
> think is only done using AT command). I see that in the Mobilink application
> (which is used with the MC950D in windows), and I also tried it and it
> works.

You really want the second AT command channel for network status updates
and especially if you wanna do extra things like SMS sending.

Regards

Marcel