Door sensor is an intelligent security equipment that can transmit through Z-Wave network and radio waves. In the ZWave network communications, door sensor can be connected to any Z-Wave gateway. Door sensor can send messages to Z-Wave gateway, then realize association with other devices. Different countries or areas, the radio frequency is different. Each door sensor has a unique ID code. When we add or remove door sensor from gateway, just place it in the Z-Wave network range of gateway. Then we can easily find the door sensor through device ID code. In the communication with ZWave gateway, door sensor can only send messages to ZWave gateway, but can not receive messages. When alarm is triggered, door sensor would send messages to gateway, then Z-Wave gateway would display the current status of door sensor. At the same time, door sensor can realize association with other devices through Z-Wave gateway. Door sensor is powered by batteries, with small body , and can be installed on the window or door easily. When door or window is open, door sensor would be triggered, then associates with other devices to work, to realize the goal of safety protection.