nRF91 AT%XICCID Command Caching & Parsing

RE: nRF91 AT%XICCID Command Caching & Parsing

dejans — Wed, 09 Jul 2025 09:44:06 GMT

Hi,

[quote user=""]In my testing when I switched between a virtual UICC (AT%CSUS=2) to the physical SIM slot 1 (AT%CSUS=0), the reported ICCID (using %XICCID) was not updated until I powered the physical SIM again by entering a CFUN=1 or similar state. Perhaps the cached XICCID value should be invalidated, or updated, when a %CSUS operation switches between UICCs.[/quote]

AT does not have SIM slot related control. It just assumes that data comes from correct SIM/cache.
This is what documentation states about %CSUS:

All Universal Subscriber Identity Module (USIM) and UICC activity is directed to the selected slot the next time the modem or UICC is activated. The slot covers also Soft SIM solutions, such as virtual iUICC, in addition to physical UICC slot.

After CSUS change, XICCID returns the initial SIM card's data until new SIM is activated. Cache value is expected to be updated when card is activated. We will have further internal discussion related to possible XICCID value invalidation or update.

Due to vacations, delayed replies should be expected. I expect to get back to you at the end of July or at the beginning of August. Thank you for your patience and understanding.

Best regards,
Dejan

RE: nRF91 AT%XICCID Command Caching & Parsing

dejans — Mon, 07 Jul 2025 18:14:32 GMT

Hi,

Thank you for your feedback, reporting of possible issue and additional information. We will take your observations internally into further consideration and look into this possible issue.
I hope to get back to you by the end of this week, but please note that replies might get delayed due to start of vacation period.

Best regards,
Dejan

RE: nRF91 AT%XICCID Command Caching & Parsing

GNotman — Mon, 07 Jul 2025 15:51:18 GMT

Hi Dejan,

This was ticket was more to provide some feedback and report a possible issue with the modem firmware, as such I'm not specifically looking for a solution. Please let me know if there is a preferred avenue for provide similar feedback.

With regards to which versions these observations apply to:

The 'at_parser' library, this behaviour was seen in SDK v2.8.0 but it appears to be the same in the latest.
The format of the %XICCID output is as defined in the AT Command manual.
The behaviour of %XICCID after using %CSUS was observed in MFW v2.0.2.

RE: nRF91 AT%XICCID Command Caching & Parsing

dejans — Fri, 04 Jul 2025 14:23:32 GMT

Hi,

Which NCS and modem firmware versions do you use?

Best regards,
Dejan