Hi all,
We are running v2.4.0 SLM in nRF-9160 as pure modem, communicating with our external MCU. And we need to send a MODBUS-TCP write request command about each 10 seconds, packets size were fixed at about 1XX Bytes.
Recently we met a problem about periodically receiving "Error\r\n" response for entering data mode with AT#XSEND at command.
It mostly occurs per 24 sends(in other words, around 240 seconds, 4 minutes), but sometimes also occurs after 4 times of AT#XSEND.
Since Error doesn't occur every time we enter data mode with XSEND, I assume the syntax MCU is sending is correct.
We've also checked the signal situation before and the power level replied by AT%CONEVAL command was 8 which refers to "Good conditions".
I really don't know what's happening now, so I decide to log the modem trace file to see if there are any hints inside.
However it looks like this is far beyond my knowledge to analysis the trace file.
So I really need help about the trace file.
I definitely see some red highlighted captured packets inside, but what does they mean?
What was the actual problem we are facing?
Are there any suggested solution?
Or any other information I should be collecting to help diagnose the situation?
Here are the modem trace log and the UART log of communication between 9160 and MCU.
Noted that the UART log and the trace log were not matched, they were logged separated.
trace file:
trace-2025-03-12T08-28-26.343Z.mtrace
========
UART logs(We logged these with a UART logger module. its not quite stable so the 9160 TX were separated into 2 files):
9160 TX
2068.9160_to_M452_FILE0000.TXT
7840.9160_to_M452_FILE0001.TXT
9160 RX:
