SMS messages using EM-12G

Hi Myron,
Please send your SMS process to me to see,thanks.

Thanks again for the response, I’m very new to all this and can’t get too technical. Instead, I’m going to try to persuade someone who actually understands what’s taking place to respond. Please bear with me and hopefully we’ll be able to get you what you need very soon.

The EM12-G is in PDU-mode, and using the AT+CMGS=length CR

syntax from 3GPP 27.005.

On being presented with the “>” prompt, the PDU is given to the modem followed by ctrl-Z

About two minutes later, the modem returns “+CMS ERROR: 350”

The same delayed error is reported when AT+CMGS=da is tried in text-mode.

This PDU-mode software works reliably on carriers other than Verizon, and has done so for many years.

We are sure the problem relates to Verizon’s use of IMS for SMS. Are there any instructions for using Quectel modems for SMS on Verizon?

Hi snowgum,
Thanks for your query in Quectel forums.
1、Without setting the PDU mode, can the SMS be sent successfully by setting the text mode.
2、Is it the same for replacing a SIM card?
3、Without setting the PDU mode, can the SMS be sent successfully by setting the text mode.

I’ll let snowgum chime in at his convenience, but to try and answer the question… we have tried to send SMS in both text mode and PDU mode and it fails every time.

I can swap the SIM card with other ones from the same carrier (Verizon or Visible) and the problem persists.

I am not the only on with this SMS problem. I know a handful of others with both the same model, as well as different model, Quectel modems and everyone on Verizon and Visible is having this SMS problem.

Yes, exactly the same problem in both PDU-mode and text-mode.

The AT+CMGS commands take about two minutes after the ctrl-Z to return “+CMS ERROR: 350”

We believe that this error is a result of Verizon using IMS for SMS.

Please see the reply by your colleague Willie Yao to a question here: Not able to send sms by AT+CMGS="mobile no"

Hello, Kerr.Yang are you still here? We would really like to get this working, please advise as to what should be done to get SMS operational. Thanks!

Hi snowguw,
Thanks for your query in Quectel forums.

Do you have our qwinlog packet capture tool? If so, please capture the log information when the problem occurs so that we can analyze the problem based on the log. If not, please provide an email address, and I will send the tool to your email address.

Thanks for your reply. I don’t have this tool.

Does it run on Windows or on Linux?

I don’t have Windows, but I think Myron does.

In any case, I’m not in the USA, so I have no access to the Verizon network.

I also think Myron’s Quectel module is internal to a router, and that router is running Linux.

Hi snowgum,
Thanks for your query in Quectel forums.
If it is a linux system, please use the QLog packet capture tool provided by our company,We need to determine the cause of this problem based on the Log information,thanks.

Thank you for the info on the linux Qlog packet capture tool. Can you provide a link to download this utility? Or is there a way to send you a private message with my email address? I don’t want to post my personal email address in this public forum. Thanks!

Hi Myron,
Can you try this Baidu cloud link?
Tell me if it doesn’t work,thanks.
link :
Extraction code :okpn

Hello Kerr.Yang,

I’ve also been working with Myron and snowgum to get this resolved. I am on Verizon and have been testing with my EM06-A and EP06-A, with the same results Myron has reported.

I have a handful of different Linux devices and have volunteered to test with Qlog, since I both have a spare device, and better access (Myron’s is remotely installed and he counts on keeping it online, so he has less freedom for testing).

I did try the baidu link above, without success. However, if your offer to email the tool still stands, my email is my forum username here (starts with n), at That should at least be enough to keep the spam tools from scraping my username from the forum too easily! :smile: I should be able to do some logging/testing on Saturday or Sunday this week if I have the tool available before then.

Thank you for your help!

Update: Myron was able to download it from your link, and I have it now. I’ll try to start working with it tomorrow if possible to get familiar with the software, and will report back as soon as I have some results to share. Thanks!


We now have a copy of QLog compiled, tested, and working on one of our test routers with this Verizon SMS issue (and one where the sim and account are verified successful for SMS with older Verizon-provided modems). I’m working to learn the software’s capabilities a little better myself in the meanwhile now. However, now that it’s working - what do you need to see, and using which filter? I have a server I can upload logs directly to, so file size won’t be an issue.

Thank you!

Hello Kerr.Yang. We are ready with QLog! Please advise what you would like captured and which filter you would like applied. After you let us know, nathhad will be able to post the info for your review. Thanks!

Thanks for your query in Quectel forums.
Can you tell me the version number of your current module? It is recommended to upgrade to the latest version for testing.The latest version should be EG21GGBR07A09M1G,thanks.

Kerr.Yang, thank you, the current modem we have set up to test for this problem is an EM06-A with firmware EM06ALAR03A05M4G.

If there is a more up to date firmware available for the EM06-A, I should be able to update before further testing as needed. I also have QLog set up on the attached router, tested, and working, and ready to capture logs to whatever instructions requested.


Thanks for your query in Quectel forums.
I have no problem using the same version of the module to test, please refer to the following test process.thanks.


[2021-02-19_17:10:26:175]Revision: EM06ALAR03A05M4G


[2021-02-19_17:10:26:762]+CSQ: 17,99

[2021-02-19_17:10:26:762]+COPS: 0,0,“CHINA MOBILE”,7

[2021-02-19_17:10:26:762]+CREG: 0,1

[2021-02-19_17:10:26:762]+CGREG: 0,1

[2021-02-19_17:10:26:762]+QNWINFO: “TDD LTE”,“46000”,“LTE BAND 41”,40936


[2021-02-19_17:10:31:855]+CSCA: “+8613800551500”,145





[2021-02-19_17:10:39:907]> 123456
[2021-02-19_17:10:46:018]+CMGS: 8


You can also send your failed AT process to let us take a look,thanks.