interrogation u201d messaging by placing a call to or establishing a communication link with the first protected premise on its list or as shown by the drawing protected premise panel number 1 i e the residential home in the drawing the protected premise panel 1 at the residential home is configured to respond to the u201c interrogation u201d message with a feedback signal indicating that it protected premise panel no 1 is operative or u201c okay u201d the receiving equipment is further configured to hang up or disconnect and proceed serially down its list to contact protected premise no 2 i e the jewelry store with a like u201c interrogation u201d message and panel no 2 responds with an appropriate feedback signal if it is okay and so on to protected premise no 3 and on through no u201c n u201d of the protected premises which upon completing its list the receiving equipment repeats the foregoing process starting again with protected premise no 1 the u201c interrogation u201d message can be more complicated than a tone but in essence the u201c interrogation u201d message corresponds to an inquiry u201c address no u2018 x u2019 do you respond u201d if there is no satisfactory response then the central alarm monitoring station follows up with further error checking to detect a compromised communication path hence fig2 depicts what has been termed the u201c receiver polling u201d technique of supervising the communication path integrity for a network system carrying automatic alarm data even though the method of operation is evident from the foregoing it will be reviewed briefly as follows for the sake of clarity the central alarm monitoring station has a host computer is configured with a special software package for handling the supervising.