Issues with TCP on RM520Q-GL over AT interface

IoT Modules 5G Module
1

I have a device that used to have the RM500Q-GL, recently I’ve decided to replicate this setup on a new device, this time with the RM520Q-GL, all seemed to worked just fine, however when I tried to open a socket over the AT interface I’d run into issues, this is the log on the new device:

ATI

Quectel
RM520N-GL
Revision: RM520NGLAAR01A08M4G

OK
AT+QGMR

RM520NGLAAR01A08M4G_01.200.01.200

OK

AT+CREG?

+CREG: 0,1

OK

AT+QNWINFO

+QNWINFO: "FDD LTE","334050","LTE BAND 7",3150

OK

AT+QIACT=1

OK

AT+QIACT?

+QIACT: 1,1,1,"10.xx.xx.xx"

OK

AT+QPING=1,"www.google.com"

OK

+QPING: 565

AT+QPING=1,"8.8.8.8"

OK

+QPING: 558

The same set of commands work just fine on the device with the RM500Q-GL, using the same SIM card, and network configuration, the only thing different is the band and channel ( “LTE BAND 4”, 2350 ). What is weird is that using RNDIS drivers yields no issues, no need to change anything related to the network, the issue is only over TCP/IP on AT commands. Am I missing something?, is any other command needed before I can open sockets?

2

Dear @bishop
Currently, which do you use? ECM, NDIS or others? You can use AT+QCFG=“usbnet”.
For QPING, it can’t have external dial up. Deactivate PDP context and try again.
You can try to open TCP socket and check if it can open or not.

3

Hi @silvia, thanks for your support, I was trying with NDIS on PDP context 1, I deactivated the PDP context and enabled a different one but no luck, it kept refusing to connect.

However, I changed it to RNDIS mode, then deactivated PDP context 1, then configured PDP context 2 according to this other post: RG520N-EU - Unable to Open a TCP connection - IoT Modules / 5G Module - Quectel Forums
and then enabled PDP context 2 and was finally able to open TCP/Sockets, I’m not sure why this worked, but at least is working now.

Regards.