TRM142 – Missing SMS network ACK causes retry loop and slot duplication

Hi everyone,

We are experiencing an issue where incoming SMS messages are repeatedly re-delivered by the operator network, often resulting in duplicate messages stored across multiple SIM slots on the TRM142 modem.

Issue Details

  1. Missing Network ACK: Even though our software reads and deletes messages immediately using AT+CMGD=<index>, the modem does not appear to properly send/register the network ACK frame with the operator’s SMSC. As a result, the operator’s retry mechanism triggers, re-sending the exact same SMS after~10 minutes.

  2. Duplicate Slot Allocation: this cause as to have duplicates of the same SMS on various slots, causing also a problem with th memory storage of the SMSs in the modem.

Is there a specific AT configuration needed to ensure automatic network ACK delivery, or is this a known firmware issue handling SMS storage flags?

Thanks for any support!

Good day,

Please post your questions regarding these devices in separate Networks group forum.

Thank you for your understanding.

Here is the link: Latest Teltonika Networks topics - Teltonika Community

Best Regards,
Imran S.