Cannot enter PSM sleep every 12hr

RE: Cannot enter PSM sleep every 12hr

Tim Chao — Wed, 26 Jul 2023 05:22:16 GMT

Oh, my bad, thanks.

RE: Cannot enter PSM sleep every 12hr

Didrik Rokhaug — Tue, 25 Jul 2023 13:40:30 GMT

[quote user="Tim Chao"]

When I tried to use "locked PLMN" as your advice , the COPS command keep return error, I don't know why.

uart:~$ at at+cops=1,2,"46692"
+CME ERROR: 0

[/quote]

When using the "at" command in the Modem Shell, you must escape the quotation marks: at AT+COPS=1,2,\"46692\"

See the note and the examples in the documentation: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples/cellular/modem_shell/README.html#at-commands

RE: Cannot enter PSM sleep every 12hr

Tim Chao — Tue, 25 Jul 2023 02:24:58 GMT

Thanks, I think you are right.

I run the test again last night, and this time, I saw cell changed and searching state report after that.

[12:00:17.060,150] <dbg> modem: handle_rrc_idle: Schedule modem off by PSM (0+30s)
[12:00:19.152,465] <dbg> modem: link_ind_handler: LTE Cell changed: Cell ID: 28662797, Tracking area: 12700
[12:00:19.152,526] <dbg> modem: link_ind_handler: LTE mode: LTE-M
[12:00:20.154,785] <dbg> modem: link_ind_handler: RRC mode: Connected
[12:00:20.282,897] <dbg> modem: pdn_event_handler: PDN 0 DEACTIVATED
[12:00:20.284,027] <dbg> modem: link_ind_handler: network registration status: Searching
[12:00:20.284,271] <inf> app_event_manager: e:net_state_event id=0x7b1b4 NET_STATE_DISCONNECTED
[12:00:21.535,644] <dbg> modem: link_ind_handler: RRC mode: Idle
[12:00:21.535,675] <dbg> modem: handle_rrc_idle: Reschedule modem off (30s)
[12:00:22.154,785] <dbg> modem: link_ind_handler: RRC mode: Connected
[12:00:24.727,691] <dbg> modem: link_ind_handler: RRC mode: Idle
[12:00:24.727,752] <dbg> modem: handle_rrc_idle: Reschedule modem off (30s)
[12:00:24.920,654] <dbg> modem: link_ind_handler: LTE Cell changed: Cell ID: -1, Tracking area: -1
[12:00:24.920,715] <dbg> modem: link_ind_handler: LTE mode: None
[12:00:54.727,844] <dbg> modem: modem_power_off: Power off modem

When I tried to use "locked PLMN" as your advice , the COPS command keep return error, I don't know why.

uart:~$ at at+cops=1,2,"46692"
+CME ERROR: 0

But at least, the modem is actually perform searching at that time as you said.

Thanks.

RE: Cannot enter PSM sleep every 12hr

Didrik Rokhaug — Mon, 24 Jul 2023 15:42:11 GMT

Hi,

What SIM card are you using, and what network are you connected to?

What happens if you don't turn off the modem after 30 seconds? Does it enter PSM eventually?

Can you take a modem trace (when you don't turn off the modem), so we can see what the modem is doing?

Best regards,

Didrik

RE: Cannot enter PSM sleep every 12hr

Achim Kraus — Mon, 24 Jul 2023 07:57:25 GMT

There may be many possibilities, one may be a HPPLMN search. That means, the SIM card is configured to search for "Higher Priorized PLMN" in intervals. It may be the case, that you SIM uses a 12h interval and has some PLMN in your country in the priorized lists. A easy way to check that is to use a "locked PLMN" and not the "auto-select". And maybe you already used a locked PLMN which then shows, that it's not a HPPLMN search in your case.