If the phone call is from the monitor center then decode the Dual Tone Multiple Frequency (DTMF) sign and order the control abject to act according to the monitor center.

• 只有识别到是监控中心拨打进来的时候，才对监控中心发送来的双音多频信号进行解码，并按照指令自动驱动被控对象进行操作；