To check network status you can use AT+CREG? command.
And, You can use command like AT+CFUN=0 and then AT+CFUN=1 to put module in flight mode and again back to normal mode. This would simulate a network reboot.
Otherwise you can use the RESET pin present on the module to restart it.
The same thing happens to me as teufber.
I am using the SIM800L for ppp in a Raspberry pi 3, but when the signal is lost for long periods the modem can not reconnect.
I do not know if the problem is at the ppp level or if the modem has frozen. The only solution is a reset?
The ppp connection attempt indicates: serial link appears to be disconnected.
Hello, I am new to sim800l with ardunio. I have a problem. I connect sim800l with cp2102 urat interface to check if sim800l is working well, I press AT ok, but ATD error, AT + cmgr error, … many more commands error, I don’t understand what is wrong, the light still flashes every 3 seconds, help me, thank you