MTSMC-H5 serial connection to data network

[mark.novak@h2powertech.com]

I am attempting to use serial pins on a MTSMC-H5 socket modem to establish a ppp interface for an embedded linux application. It looks like I can connect to the voice network (confirmed with sms), but I’m not having much success with data.

I would be grateful for any advice, insights and/or guidance.

Thanks and best regards,

Mark

[Steve Kovarik]

Hi Mark

Aside from providing power and ground, please ground any low active inputs
RTS (Pin33) and DTR (pin40).
Also issue AT Commands to the modem at 115200bps, 8, none, 1

-Best Regards

[Steve Kovarik]

Mark

For a successful packet data connection you would need to program the APN
associated with the SIM card into the modem with the command at+cgdcont=1,”IP”,”yourAPN”

Then in Linux the dial number should be *99***1#

[mark.novak@h2powertech.com]

Hi Steve,

I’ve confirmed that RTS and DTR are grounded.

The embedded linux application is using wvdial as a ppp dialer. /etc/wvdial.conf is as follows:

[Dialer Defaults]
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Baud = 115200
Modem Type = Analog Modem
Password = " "
Username = " "
New PPPD = no

[Dialer netConnect]
Init3 = AT+CGDCONT=1,"IP","i2gold"
Stupid Mode = yes
ISDN = 0
Modem = /dev/ttyO4
Phone = *99***1#

This appears to successfully connect the modem, but the ppp0 interface is not created, despite the pppd startup:

--> WvDial: Internet dialer version 1.61
--> Cannot set information for serial port.
--> Initializing modem.
--> Sending: ATZ
OK
--> Sending: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
OK
--> Sending: AT+CGDCONT=1,"IP","i2gold"
AT+CGDCONT=1,"IP","i2gold"
OK
--> Modem initialized.
--> Sending: ATDT*99***1#
--> Waiting for carrier.
ATDT*99***1#
CONNECT
--> Carrier detected.  Starting PPP immediately.
--> Starting pppd at Fri Jul 12 13:59:41 2019
--> Pid of pppd: 1640

I am struggling to discern where the failure point is in the chain from [modem] → [/dev/ttyO4] → [wvdial] → [pppd]

For reference, I’ve had success with the MTSMC-H5-U version of the socket modem using a USB connection. In that scenario, I can specify Modem = /dev/ttyACM0; pppd then creates the ppp0 interface upon connection.

At any rate, thanks for your help. Please let me know if you have any additional thoughts or possible tests that might be useful.

Best regards,

Mark

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