nrf9160 B0 long connection time??

[Martin.T]

Hello,

we are using the nrf9160 in one of our products. Our assembler has used old nrf9160 SICA B0 chips on our first protoyping round. When we run our software on the nrf9160 DK developement board than we get 1 or 2 sec a connection. On our custom board need the same software at least 10 seconds or more to establish a connection. Both devices (DK board and custom hardware) have modem fw 1.2.3 installed and connect over nb-iot Both devices are choosing channel 8 for the connection.

Now we are not sure what is causing this problem. Its this because we have the B0 chip instead of B1 (which is mounted on the DK board). Or do we have a other unknown hardwareproblem?

[Didrik Rokhaug]

Hi,

Is this the first time the device are connected to the network?

The modem stores information about the networks it is connected to (though it might not be written to flash immediately), to help speed up subsequent connections.

I am not aware of any major performance differences when it comes to network connection time between the two SiP revisions.

If you turn the modem off with AT+CFUN=0, this will trigger a flash write, so the network parameters are stored in flash. That should make the connection time similar to what you see on the DK, assuming there are no other problems.

Best regards,

Didrik

[Martin.T]

Hi, 

many thanks: Use the command AT+CFUN=0 before power off, was the solution of the problem.

Best regards!