How to reconnect to the gsm network/carrier?


#1

Hi,
If the q2686 goes out of reception range, the flash-led stays on solid (this is correct, shows we are not connected). However, when we go back into reception area, how do we get it to connect back to the gsm netowrk automatically? is there a command? or should i have a timer to check if it is connected or not connected to the gsm network?
for some reason, at+csq gives 99,99 even once we go back into an area with full reception!!!
why? or how do i get it to change that?

Thanks.

atdxxxxxxxx returns “NO CARRIER”
how do i get it to re-connect to the carrier?!?!


#2

Hm, when i go out of range/in of range it reconnects automatically.
622_Q2686

(Tested with connectect/disconnected antenna)


#3

Look-up AT+COPS

Also AT+CREG


#4

You don’t. I have had this problem a lot. The module should reconnect automatically. Sometimes (most of the time) that works. But if it doesn’t, the module can be in an undefined state for hours. Back in the days of FW 6.62 you had no other choice but to reboot the unit. Nowadays you can manually define a timeout for yourself, after which you consider a re-connection to be unlikely and hence initiate a manual reboot.
+CREG just gives you some info about the connection state, it’s no help at all. Tricks like issueing AT+COPS=2 and the AT+COPS=0 don’t remedy either.
After more than two years of Wavecom experience including a lot of coding and tweaking in can positively say that Wavecom products are not stable enough when it comes to reliability. If your unit is stationary you might be lucky, but the situation “underway” is still catastrophic… I hope that helps :slight_smile:

Best regards,

wismo_coder


#5

wismo_coder:

And how about the AT+COPS=? command?
The response for that one takes about 10 secs, so I assume that it actually communicates with the GSM network…
What do you think?


#6

Again, that just provides information about available operators - it doesn’t actually make the unit reconnect.


#7

Yes, I know.
The problem is that this information is sometimes not correct (e.g. the home network is available, but the modem still gives +CREG = 2,2 response).

I was hoping that maybe the AT+COPS=? command forces the modem to refresh this information.
Is that correct?