How to realize Zigbee door lock offline mechanism?

After the Zigbee door lock is equipped with a network, if the Zigbee network is reliable and the connection between the Zigbee gateway and the server is stable, the Zigbee door lock will always be online. If the app (server) wants to send instructions to the door lock in the online state, the normal time is 5s. The internal door lock will be received. If the network status is not good, there will be a certain delay (not more than 30s). If it cannot be sent to the hardware after more than 30s, the transmission fails; when the Zigbee gateway is suddenly offline (power off, network off), the Zigbee door The lock will immediately go offline, and if the gateway comes back online, the Zigbee door lock will immediately return to the Internet; if the Zigbee door lock itself disconnects from the network (the door lock is powered off, or the network is disconnected due to a bad signal), the app is the most The door lock will display offline for less than 5 minutes. If the door lock is replaced with a battery or a door opening operation is performed, if the network is reliable, the door lock will immediately resume networking.