Need Modem Trace Log analysis about MODBUS-TCP under SLM data mode transmitting failure

RE: Need Modem Trace Log analysis about MODBUS-TCP under SLM data mode transmitting failure

Hakon — Tue, 01 Jul 2025 08:21:47 GMT

Modem team;

Given that the failure is in processing the AT-command AT#XSEND, which enters datamode, but does not actually send anything to network at this point, the issue is almost certainly in the UART implementation. Either the AT#XSEND commands is corrupted or the uart_rx_enable(or something related to that fails).

Debug level RTT traces would tell more, but the v2.4.0 SLM UART implementation is known to be unstable. It was fixed with this PR:

https://github.com/nrfconnect/sdk-nrf/pull/11416 for the v2.5.0.

I would recommend trying this with SLM v2.5.0, or newer, or cherry-picking the above (rather large) PR for the v2.4.0.

RE: Need Modem Trace Log analysis about MODBUS-TCP under SLM data mode transmitting failure

Hakon — Fri, 27 Jun 2025 08:08:13 GMT

Hey,

I have taken this over now. I forwarded your trace file to the modem team.

RE: Need Modem Trace Log analysis about MODBUS-TCP under SLM data mode transmitting failure

Jeffery — Mon, 17 Mar 2025 00:45:55 GMT

Hi Nordic team

How about the analysis for attached trace file?

Thanks

Jeff