Cannot send long (concantenated SMS) with EG25-G

IoT Modules LTE Standard Module
1

Hi! We have an issue where the Mulritech L4G1 modem will stop responding and encounter error when we send long SMS (concantenated).

The modem information: Quectel EG25 Revision: EG25GGBR07A08M2G, MODEM-IMEI: 860195052143028

Happen on all L4G1 modems.

Can you advise?

The modem simply does not respond to any AT command after sending a few messages. We are using Linux kernel 4.19.134

Please assist

2

Hello Jswong,
You can use AT+QCMGS send Concatenated Messages, the specific reference method is shown in the picture below, thank you.

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3

Hi! We are using PDU mode. Any pointers when we send in PDU mode? We face Error 350 when sending long message with long message.

4

This is a huge topic, with so many individual aspects of PDU encoding to get correct.

Can you provide an example set of your PDUs for a single (failing) concatenated message? By all means use a token destination address rather than a real one.

5

hi Jswong,
For PDU mode, you need execute AT+CMGF=0 to query the message formate is PDU mode, then you can send PDU message.