Milesight router supports sending or receiving SMS, you can refer to this article for more information. In this document, we will guide you some check list and some common issues for reference.


1. Confirm the SIM cardcan send and receive SMS on your mobile phone.

2. Check whether the SIM card is installed well.

3. Check Antenna’s connection, and put it into a proper place to provider good signal.

4. Check the cellular configuration, especially the SMS Center.

5. Check the SMS Mode, PDU is recommended.

6. Check if the Phone Group setting is correct.

7. Check if the SMS command is correct, you can refer to this document for more detail.

8. Enable the debug option in Maintenance->Log->Log settings

After runnning a few minutes, download the full log for deeper check, especially the cellular.log and system.log

Trouble shooting Examples:

1. SIM card is not able to send SMS

If SIM card can not send SMS, like special-purpose for IOT without SMS function, you may encounter CMS ERROR: unknown error.

2. A wrong SMS center is configured

If you configured a wrong SMS center, you may encounter CMS ERROR: unknown error, after a 2 minutes no respond.

3. SMS length too long for text mode

If you choose text SMS mode, and send a SMS over 160 characters, you may encounter CMS ERROR: invalid text mode parameter.