... Inbulit siren :can play human voice It is learn facility I/Ofunction by wire silent /siren -we can set up ... - receiver send singal to ip camera or dvr by I/Ofunction by wire silent /siren -we can set up ... receiver has 3 pairs of interface , one is for I/O,the rest for wired sensor (wired PIR)2.as for ... panic button -just send signal to IP camera by I/Ofunction without receiver''s siren or alarm voice ,the ...