Online deep sleep mode questions

Telematics
1

I’m testing a couple of devices (FMC920 and FMC234) to potentially add them to our fleet, but I can’t figure out how to use Online Deep Sleep properly.

If I enable it with the default settings, the devices go to sleep and the connection to the server is closed once the Open Link Timeout expires. If I increase the Open Link Timeout, then the device never enters sleep mode. In the logs I also see:

“Sleep: 3, not allowed! Reason: Some socket opened.”

What I need is for the device to enter Online Deep Sleep while still being able to receive commands from the server. Is that possible?

2

Hello,

The Online Deep Sleep mode sets the GNSS receiver to sleep mode without deregistering from the GSM network. This means that the device can still send and receive SMS messages and make or receive calls. Additionally, it does not close the GPRS context if one was previously opened.

Please note that the conditions required to enter Online Deep Sleep mode are the same as those for entering Deep Sleep mode.

  • FMC920 is configured in Deep Sleep mode and sleep timeout is reached;
  • Device time must be synchronized with GPS satellites.
  • Ignition (configured ignition source) is off;
  • Movement is not detected by the accelerometer or configured movement source;
  • Min. Record Saving Period (Data Acquisition Mode settings) must be larger than Open Link Timeout parameter, so that FMC920 could close GPRS link;
  • The difference between Send Period (Data Acquisition Mode settings) and Open Link Timeout must be more than 90 seconds, so that FMC920 could close GPRS link within at least 90 seconds;
  • There are no SMS messages being received;
  • Data socket(s) are closed;
  • Data sending is not in progress;
  • FOTA is not in progress.

The parts of the text highlighted in bold indicate that the device is required to close the connection with the server in order to enter Online Deep Sleep mode.

Therefore, it is not possible for the device to enter Online Deep Sleep while still being able to receive commands from the server.

If you need a mode that saves energy but keeps the device registered to the server link, you should consider using GNSS Sleep mode instead.

Best Regards

Oscar B