Edrx cycle consumption and unnecessary pulses at 502 milli seconds interval

IoT Modules LPWA Module
1

Hello,

I am using BG-95 M2 modem with cat-m1 network.

I have configured modem successfully for eDRX with cycle 40.96 seconds and ptw 1.28 seconds.

As per my requirement my host (microcontroller-based device) must be always connected MQTT broker so the host application (cloud-based subscriber) can request data anytime with acceptable eDRX cycle delay.

So, following configuration i did to modem

DIsable USB

AT+QCFGEXT=“disusb”,1
OK

1]Registration

2]eDRX enable

AT+QPTWEDRXS=2,4,“0000”,“0011”
OK
AT+CEDRXRDP
+CEDRXRDP: 4,“0011”,“0011”,“0000”
OK

Enable sleep mode

AT+QSCLK=1
OK

3]TCP and MQTT related configuration

AT+QIACT=1
OK
AT+QIACT?
+QIACT: 1,1,1,“IP”
OK

AT+QMTCFG=“version”,0,4
OK

AT+QMTCFG=“pdpcid”,0,1
OK

AT+QMTCFG=“keepalive”,0,0
OK

AT+QMTCFG=“session”,0,0
OK

AT+QMTCFG=“timeout”,0,15,3,1
OK

AT+QMTCFG=“recv/mode”,0
+QMTCFG: “recv/mode”,0,0
OK

AT+QMTOPEN?
OK

AT+QMTOPEN=0,“IP”,1883
+QMTOPEN: 0,0

AT+QMTCONN?
+QMTCONN: 0,1
OK

AT+QMTCONN=0,“Client ID”,“Username”,“password”
+QMTCONN: 0,0,0

AT+QMTSUB=0,1,“spBv1.0/Group_ID/NCMD/Edge_ID”,1
+QMTSUB: 0,1,0,1

4] RRC Idle

+QCSCON: 1,0

Set DTR Pin High

5]After RRC idle i can see eDRX cycle execution

image
image1626×830 120 KB

6]Unnecessary periodic pulse of 40mA with periodicity 500 milliseconds observed throughout the eDRX cycle.

This has increasing current consumption.

Why is this happening?

Do i need to change any modem related configuration?

Is this due to Modem firmware or network requirement as per 3GPP specifications?

Attached power profiler log below.

eDRX-40-96-ptw-1-28.zip (957.9 KB)

Thank you

2

Hi @devendra.chaudhari

Have you connect USB cable?

3

Yes, while configuring modem I have disabled USB.

Enabled sleep mode

AT+QSCLK=1
OK

After modem gives RRC disconnection.
DTR pin pulled up (High state.) for modem sleep state.

As our eDRX cycle is 40.96 seconds, I have confirmed that modem able to receive data from network at the PTW time else modem remain in sleep state.

If you have power consumption graph with eDRX cycle enable and modem is in continuous connection (to MQTT broker). Could you please share such power consumption graph.

Thank you

4

Hi @devendra.chaudhari

Probably caused by MQTT keepalive? its better to provide modem log to analysis.

5

Hello, please refer the attached log. Keepalive is configured as 0.

In logs when host microcontroller receives +QNTP URC, it will put modem into sleep state by pulling up DTR pin.

telenor_public_sim_edrx_12-08-26.zip (1.9 KB)

6

Hi
we need module log from attach network to idle. And, BTW, please disconnect USB cable even usb feature disabled. Also, please provide module version.

7

Hi, USB is disabled and no cable attached to modem USB port.

Could you please tell How to take Modem logs (Detailed procedure to get modem logs)

Thank you.

8

Hello,

I tried with AT+QCFG=“dbgctl”,0 to get debug logs on modem debug UART with1.8V operated USB to TTL convertor. but didn’t get any log on UART. USB is already disabled.

Modem firmware for BG95-M3: BG95M3LAR02A03_01.200.01.200

Modem firmware for BG95-M2:BG95M2LAR02A04_01.009.01.009

I am using both modems.

Could you please share the procedure to get logs on modem debug UART port.

Thank you.