HL 7692 Low power with SMS

Hi,
which is the correct way to put the HL7692 in lowest power consumption possible but able to receive SMS?
Please note the module is connected via UART

have you tried the sleep mode which stated in PTS?

Currently we are using
AT+CGATT=0
AT+KSLEEP=0 plus DTR

is this the correct way? I’m asking because we wake up the module using DTR and sending
AT+CGATT=1 But often this last command (AT+CGATT=1) hangs for something like 2 o 3 minutes. Sometimes is immediate, under the same network conditions.
Please note after exiting sleep and before sending AT+CGATT=1 we test the module response sending “AT” command and it always respond in a few milliseconds.

How about not entering at+cgatt=0?
Will it consume more power?

Btw, can you receive the sms with DTR deasserted?

Also have you tuned DRX value?

How about not entering at+cgatt=0?
Will it consume more power?

Yes, we done some tests in the past and we noticed the power consumption was higher without at+cgatt=0.
Unfortunately I don’t have that data in my hand now.

Btw, can you receive the sms with DTR deasserted?

When DTR is deactivated (high electrical level) we can receive SMS watching the “ring” physical pin and waking up the module.

Also have you tuned DRX value?

No, I don’t know nothing about DRX, can you address me?

Best regards

Are you using LTE network

Are you using LTE network

Yes we are using both LTE / 2G

For DRX, you can refer to AT command guide, i saw there is some setting for drx

Btw, can you restart telecom stack by +cfun instead of +cgatt after wake up?

For DRX, you can refer to AT command guide, i saw there is some setting for drx

The only reference in the manual are DRX_Timer_Max and drx_cycle_length under +CGED command.
Are you referring to these?

Btw, can you restart telecom stack by +cfun instead of +cgatt after wake up?

Yes, I can try.
Should I use AT+CFUN=37 (Reset single stack) or AT+CFUN=38 (Reset all stacks) or any other param?

How about

At+cfun=0
At+cfun=1

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Hi @jyijyi

I’ve done some tests on power consumption with/without using cgatt=0 when modem is in sleep mode (KSLEEP=0, DTR high level).

Whit CGATT=0 the device consume ~6mA
Without CGATT=0 the device consume ~19mA

Both tests were done under good LTE coverage

This is a huge difference for us, and 19mA is far above the technical specification worst case scenario that is 6.7mA
Are we missing something ?

I attached a chart of power consumption without sending CGATT=0: as you can see every ~50sec the module go from ~2mA to +100mA for 10 seconds.

Please let me know

ps: we had the same result using KSLEEP=1

You can still use at+cgatt=0 then.

  1. At+cgatt=0
  2. Sleep mode is entered
  3. To wake up, type AT+KSLEEP=0 plus DTR
  4. at+cfun=0
  5. at+cfun=1