10 years, 2 months ago.

ppp connection with Ublox C027

Hi All,

we are trying to get our Ublox Lisa-U200 modem. Both on a developer board and on the C027. We are using the Vodafone M2M SIM which works fine on our Huawei modems. We have got the bug down to the PPP negotiation.

From a terminal like screen or cutecom we are initiating the AT command to connect. The idea being that the PPP negotiation will be done by the by software running on the mbed. On the Huawei we get the 'CONNECT' message. The Ublox seems to be trying to do the PPP negotiation on the modem - and failing. We think this is because the Ublox modem is trying to do the PPP negociation.

Below is the output from the console:

AT console output with Ublox Lisa U-200




~\0xff}#\0xc0!}!}!} }4}"}&} } } } }%}&+},X\0xfb}'}"}(}"Z}(~~\0xff}#\0xc0!}!}!} }4}"}&} } } } }%}&+},X\0xfb}'}"}(}"Z}(~~\0xff}#\0xc0!}!}!} }4}"}&} } } } }%}&+},X\0xfb}'}"}(}"Z}(~~\0xff}#\0xc0!}!}!} }4}"}&} } } } }%}&+},X\0xfb}'}"}(}"Z}(~~\0xff}#\0xc0!}!}!} }4}"}&} } } } }%}&+},X\0xfb}'}"}(}"Z}(~~\0xff}#\0xc0!}!}!} }4}"}&} } } } }%}&+},X\0xfb}'}"}(}"Z}(~~\0xff}#\0xc0!}!}!} }4}"}&} } } } }%}&+},X\0xfb}'}"}(}"Z}(~~\0xff}#\0xc0!}!}!} }4}"}&} } } } }%}&+},X\0xfb}'}"}(}"Z}(~~\0xff}#\0xc0!}!}!} }4}"}&} } } } }%}&+},X\0xfb}'}"}(}"Z}(~~\0xff}#\0xc0!}!}!} }4}"}&} } } } }%}&+},X\0xfb}'}"}(}"Z}(~

Does anyone know why the modem is returning output on the ATDT *99# shown above?

Kind regards, Nicholas.

Question relating to:

The u-blox-C027 is a complete starter kit that allows quick prototyping of a variety of applications for the Internet of Things. The application board has a MAX-M8Q GPS/GNSS receiver and …

Yes, I know the answer to this kind sir.

It seems that the LISA tries to be helpful for you and to negotiate the PPP session on your behalf. Unfortunately this is quite the problem when your PPP session is many doge.

The solution in this case is to prefix the APN with PAP like this:

<<code title="so coding">>at+cgdcont=1,"IP","PAP:apn_name"<</code>>.

And then sir, your modem should work like a golden sparkly good thing.

posted by Ashley Mills 20 Feb 2014
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