The present invention is for a sensing device that monitors the conditions of a remote location. The device has a detecting means which detects the conditions at the remote location; a transmitting module that reads and remotely transmits information containing the detected conditions and the power level of a power source powering the transmitting module; a base module that receives, selectively processes and conveys the information telephonically; and an identifying means that identifies the remote location of the call before the call is completed, and thus the information can be passed without completing a call. The invention is also directed to a method of sensing conditions at a remote location in the least possible time. The invention is further improved by devising a system and technique which enables the transfer data (1 bit or more) from a remote location to a primary location utilizing, in one example, only a single telephone line at the remote location and as few as only two telephone lines at the primary location.