1 Tranceive Data+ (发信号+)2 Tranceive Data- (发信号-)3 Receive Data+ (收信号+)4 Not connected (空脚)5 Not connected (空脚)6 Receive Data- (收信号-)7 Not connected (空脚)8 Not connected (空脚)4578 作电话线或者传真机用
