我用的是西门子mc55模块，at程序如下，请高手指点一下。
AT
OK
AT+CGDCONT=1,"IP","CMNET"
OK
AT+CGATT=1
OK
AT+CGACT=1
ERROR //这里总返回错误，头大了
AT+CGPADDR=1
+CGPADDR: 1,""
OK
ATD*99***1#
CONNECT
~}#!}!}#} }9}"}&} }*} } }'}"}(}"}%}&4u4}#}%#}%mA~~}#!}!}#} }9}"}&} }*} } }'}"}(}"}%}&4u4}#}%#}%mA~~}#!}!}#} }9}"}&} }*} } }'}"}(}"}%}&4u4}#}%#}%mA~~}#!}!}#} }9}"}&} }*} } }'}"}(}"}%}&4u4}#}%#}%mA~~}#!}!}#} }9}"}&} }*} } }'}"}(}"}%}&4u4}#}%#}%mA~~}#!}!}#} }9}"}&} }*} } }'}"}(}"}%}&4u4}#}%#}%mA~~}#!}!}#} }9}"}&} }*} } }'}"}(}"}%}&4u4}#}%#}%mA~~}#!}!}#} }9}"}&} }*} } }'}"}(}"}%}&4u4}#}%#}%mA~~}#!}!}#} }9}"}&} }*} } }'}"}(}"}%}&4u4}#}%#}%mA~~}#!}!}#} }9}"}&} }*} } }'}"}(}"}%}&4u4}#}%#}%mA~  //这里总返回乱码，头晕了。
NO CARRIER//无载波