说明：  移远模块AT指令说明书，详细解释各种AT指令的用法。
(his document gives details of the AT Command Set supported by Quectel NB-IoT BC95 module. The following string will be output after booting the module: <CR><LF>Neul<CR><LF>OK<CR><LF> After this string has been received, the AT command processor is ready to accept AT commands. If BC95 module Quectel is rebooted or restarted for any reason hat is not a normal power-on sequence, a message would be output before the <CR><LF>Neul<CR><LF>OK<CR><LF> string. Please refer to Chapter 8 for more details.)