# 

* AT+QMTOPEN=0,"base.codestudios.cn",1883
* AT+QMTCLOSE=0

* AT+QMTCONN=0,"BC20"
* AT+QMTDISC=0

* AT+QMTSUB=0,0,"demo",0
* AT+QMTUNS=0,"demo"

* AT+QMTPUBEX=0,0,0,0,"4g",4
* ABCD