Nrf9160 not setting requested active time

[PieterK]

Good day I am wondering if you can help me.

For background information.

Network - NB-iot

Firmware -  1.3.1

Software - Serial LTE Modem

Hardware - nrf9160dk

I am trying to set the requested active time down so that when I go into idle to save power and keep my IP connection that the modem doesn't stay active for 60 seconds there after.

The device is going into low power mode but only after 60 seconds. 

I will attach a screen shot of the AT-commands that I take to get to the point where I'd like to go into low power but the Requested Active Time does not change.

I came across this following link while attempting to get my power consumption down.

(+) turn off active time and go directly to power save mode - Nordic Q&A - Nordic DevZone - Nordic DevZone (nordicsemi.com)

I tried the command AT+CPSMS=1,"","","10101010","00000000" to set the periodic TAU to 10 minutes and the requested active time to 0 and to 2 (00000001) seconds.

But they had no influence on the 60 seconds of high power consumption after issuing the AT#XSLEEP=2 to put the system into idle.

If anyone has any input as to where I am going wrong I will greatly appreciate it.

[Albrecht Markus Schellenberger]

PieterK said:

Thank you very much for all the help.

My pleasure, Pieter! I’m glad I can help :-)

PieterK said:

Here is the steps I took according to your steps.

What I can see in the log is that the modem:

(11:00:12.926) +CEREG: 1,"5209","09A53917",9,,,"00000000","10010100"

Successfully establishes a connection to the network.

(11:01:13.267) %CESQ: 255,0,255,0

Releases the active session and goes into idle. The delay from RRC connected to RRC idle is network specific and can not be affected by the UE.

(11:01:13.304) %XMODEMSLEEP: 1,599999

Is entering sleep mode directly afterwards.

Hence, the nRF9160 goes into PSM as soon as possible, which also is < 60s and that looks correct to me. If you perform the same steps with the Serial LTE modem application, do you get a similar result?

Regards,

Markus