我正在尝试向我的串行端口发送命令，我的 USB 上有一个调制解调器，我无法连接 putty 或 minicom 来发送 AT 命令。
dmesg | grep tty
[265301.769187] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB0
[265766.120545] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0
[265848.450853] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB0
[266256.553290] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0
[266296.890902] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB0
[267710.969347] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0
[267735.962921] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB0
[267772.749423] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0
[267807.950927] usb 2-5: GSM modem (1-port) converter now attached to ttyUSB0
当在 minicom 上返回时：
Serial device: /dev/tty8;