Hello. We are developing a solution based on Quectel M35 modems and chrome browser. Accordingly, our software is written in js. Faced with such a problem: if SMS messages start coming during operation, and at the same time execute the USSD command, the modem issues errors +CUSD: 4 CME Error: unknown and no longer responds to USSD commands. That is, a CME Error is always issued for any ussd command. This is fixed only by rebooting the modem via AT+CFUN=0.1 and then AT+CFUN=1. It seems to us that this is a bad practice. Perhaps there is a more regular, correct solution to this problem? The modem memory is not overflowing with SMS messages, we broadcast them to the COM port and do not store them in memory (when initializing the modem, we execute the command AT+CNMI=2,2,2,1,0), but still when receiving SMS messages, the modem hangs if we run ussd
Hi
Sorry, the M35 module has been discontinued, and we are not familiar with the function of uusd.