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

Networking Solutions Question
1

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!