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Measure Power Consumption in Power Saving Modes - OTII tool demo

Tutorial, January 14, 2021 - 10:16am, 544 views

This presentation describes the procedure and setup for demonstrating power measurement on EXS82-w module in Power Saving Modes - eDRX & PSM.

PSM and eDRX are described LTE Cat-M and NB-IoT networks.

Jumper settings and DevKit connection to OTII tool.

Module sleep mode explained.

demonstration + power graphs discussion.

 

 

pdelrot_samea's picture
pdelrot_samea

Hello, thanks for this tutorial.
I spend my day to try the different AT commands for Sleep, Suspend, PSM and eDRX, with the OTII tool too, on the AN95 basis.

This tutorial definitively gave me some examples and results that I shall expect with the EXS82-W I have.

To conclude, sleep mode is working on my side, results and values as given in your tutorial.

But I think my LTE network do not support PSM at all. My paging period never changes, except my different settings are accepted by the modem, which tries to negociate with the network (CEREG varies on my setup). Suspend mode never send an URC.

So just one question, is there any pre-requisites to activate the PSM ?
Best regards,

Pascal

odi.odi's picture
odi.odi

Hi Pascal,

great to read that you've been able to reach that status.
Did you know that Thales provided a video series as well describing the whole setup of measuring the power consumption from A-Z:

https://www.thalesgroup.com/en/markets/digital-identity-and-security/iot/resources/developers#poweroptimisation

If you prefer to read, there is a blog on Digikey:
https://www.digikey.de/en/articles/how-to-enable-power-saving-modes-of-nb-iot-and-cat-m

If the network does support PSM or not, could be seen only after setting at+cereg=4
The coming URC or further at-reply: at+cereg?
will through something like: 

+CEREG: 5,5,C2F6,031B7B65,9,,,00000001,10101110

...where the last 2 binary numbers indicate the active time T3324 and the periodic TAU timer T3412.
If they are not present, the network does not support PSM.

Be aware, that your requested PSM values via at+cpsms are 'a wish' only.
The final decision which values you get is on the network side.
You can btw. translate the output at the bottom of the PSM calculator page here:
https://www.thalesgroup.com/en/markets/digital-identity-and-security/iot/resources/developers/psm-calculation-tool
 

To get the missing URCs, you need to activate them via:
at^scfg=suspendavailable,1
at^scfg=suspendready,1

Hope this helps,
Markus

 

 

ASHVARTS