Intrusion detection is often viewed as part of the ACS because most door controls for access control can alarm when the door is left open or opened without a valid authorization. These systems use everything from simple switches to complex devices that detect motion, heat, glass breaking, or other nonstandard occurrences in the area to detect the presence of persons in secure zones. Intrusion detection systems (IDSs) can generate simple local or paging alarms or can be integrated with other systems to provide more active responses (e.g. turning on cameras or lighting). WBS intrusion detection solution include fire detection alarm, access point alarm, burglary alert/alarm.