Limiting the amount of data received from AT#XRECV command.

RE: Limiting the amount of data received from AT#XRECV command.

Syed Maysum Abbas Zaidi — Mon, 23 Feb 2026 07:39:36 GMT

Hi,

Yes its correct that the old Serial LTE Modem (SLM) application does not have the new version of #XRECV command. It has been added in the Serial Modem Application which is available from NCS v3.2.0.

So either you start using newer NCS version (simpler) or if you want you can also migrate from the SLM to serial modem by making changes as mentioned in this link.

Best Regards,
Syed Maysum

RE: Limiting the amount of data received from AT#XRECV command.

Daniel B. J. — Fri, 20 Feb 2026 11:01:31 GMT

Hi,

I've run some test using the nRF91 firmware binaries v2.04 and the serial LTE modem firmware, and the at commands shown in the link you provided does not seem to match with the firmware I've tested.

What firmware should i download/build in order to use that version of the #XRECV command?

Kind regards, Daniel

RE: Limiting the amount of data received from AT#XRECV command.

Daniel B. J. — Thu, 19 Feb 2026 10:06:59 GMT

Hi,

Perfect, thank you.

It seems I had bookmarked an older version of the at-firmware documentation with a simpler version of #XRECV described.

Kind Regards,

Daniel.

RE: Limiting the amount of data received from AT#XRECV command.

Syed Maysum Abbas Zaidi — Thu, 19 Feb 2026 09:27:57 GMT

Hi,

Yes, #XRECV supports small reads. It has an optional <data_len> argument that lets you specify the maximum number of bytes to receive from the socket in a single call.
However, this only limits how much data is read per #XRECV and does not replace UART hardware flow control. If the Serial Modem UART RX buffers fill up, it will disable UART reception. Whereas when hw flow control (RTS/CTS) is enabled, the modem can pause the sender, but without it incoming UART data may be dropped. Therefore, its sill recommended to add at least CTS.

Best Regards,
Syed Maysum