nRF9160 SLM data mode exit

[yesheng]

Hi,

I'm using nRF9160 to send real-time data over MQTT. I'm doing 1 MQTT publish per second. It works most of the time, however, I noticed that the modem couldn't exit the data mode occasionally. I append "+++" at the end of the data, but the modem remains in the data mode. Any suggestions on how to exit data mode correctly?

I'm using SLM 2.0.2 with modem FW 1.3.2

Thanks,

[Øyvind]

Hello, 

Due to Christmas Holidays our team is lower staffed than normal and some delays in our answers must be expected. We apologize for the inconvenience.

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I will have a look at your ticket and get back to within today or tomorrow.

Kind regards,
Øyvind

[Øyvind]

Hello, are you getting any errors in RTT or log output?

Kind regards,
Øyvind

[Øyvind]

Thanks for clarifying. Sorry for the late answer. 

Can you provide the commands that you send from the host MCU to the SLM device? What signal does your state machine receive from the SLM?

[yesheng]

Hi Øyvind,

I'm using AT#XMQTTPUB to enter data mode, the payload comes after this. The payload ends with "+++", which tells the modem to leave the data mode.

Once the modem is stuck in the data mode, the next AT#XMQTTPUB will be treated as part of the payload. Hence, I can see the "+++AT#XMQTTPUB" in the MQTT broker.

My hypothesis is the modem for some reason stuck in "datamode off pending" state for a little longer. Hence, the modem still sends everything it receives until it actually leaves the datamode. 

[Øyvind]

Do you receive "#XDATAMODE: 0"? According to our developers you must wait for this, and refer to the latest version of the SLM documentation on Exiting data mode.

[yesheng]

Hi Øyvind,

I think 2.0.2 doesn't send this. Instead, it sends "OK" when the modem sent the message successfully.

However, I'm still a bit confused about how to utilize #XDATAMODE:0. Do I keep sending "+++" every now and then until the modem returns  "#XDATAMODE: 0"? This approach seems a bit ineffective.

Thanks,

[Øyvind]

Hello, 
are you able to share more information on the MQTT payload? I would like to reproduce the issue on my side, but will need more information on your setup on both modem side and host side please. 

Thanks

Kind regards,
Øyvind