PPP on MC7750

IoT Modules MC/EM Series
1

Hi
I know that we should use Gobi to establish LTE data connection on MC7750 for the sake of high performance and low latency, but my Linux version is too low to support Gobi driver - as a sequence I want to try legacy PPP protocol on MC7750,

I did try PPP connection over MC7750 serial port but it always fails to get IP address from PPP server. Before making PPP connection, I issue AT command: AT+CREG?, and modem replies+CREG?: 0, 0. It means the modem doesn’t activate the LTE PDP yet.

I did try command: AT+CGDCONT=1,“IP”,“apn.vzinternet.com” - modem returns OK but modem is still not in packet mode.

Do you know any AT command to activate LTE PDP context, or AT command sequences to get PPP working on MC7750.

Thanks

2

Hi,

Is “apn.vzinternet.com” the correct APN to use with your SIM/subscription?

Found that APN “vzwinternet” was used in most case, also please check MC7750 status using AT!GSATUS? command.

Thanks.

3

Thanks lotam. Here is the outcome of AT!GSTATUS?

at!gstatus?
!GSTATUS:
Current Time: 65728 Temperature: 48
Bootup Time: 1 Mode: ONLINE
System mode: LTE PS state: Attached
LTE band: B13 LTE bw: 10 MHz
LTE Rx chan: 5230 LTE Tx chan: 23230
EMM state: Registered Normal Service

RSSI (dBm): -62
RSRP (dBm): -85 TAC: 0001 (1)
RSRQ (dB): -9 Cell ID: 00000100 (256)
SINR (dB): 28.8

OK

Modem status looks OK to me.

I am connecting modem with R&D wideband radio communication tester, and the SIM doesn’t care about apn.
I tested other Sierra LTE modules - MC7700 and MC7710, both work perfectly with tester. I just stuck with MC7750 in PPP mode.

Thanks

4

Hi,

I don’t have chance to try PPP on tester… and your !GSTATUS response looks normal.

Maybe you can try enable the !IMSTESTMODE command?

AT!ENTERCND=“A710”
AT!IMSTESTMODE=1
AT!RESET

then before you start PPP, send both AT!GSTATUS? and AT+CGCONTRDP to check the response.

Also, are you able to contact your FAE or distributor for better support?
I am afraid it maybe not easy nor efficient to support you here…

Thx