Support 200 groups of numbers, each group of numbers can be set to control the relay within a specified time period. One relay output, it will be closed after the authorized number calls in, and it will be automatically disconnected after the set time is reached. After the authorized mobile phone controls the relay, it can send operation messages to the user. Between 0 and 999 seconds, the closing time of the relay can be controlled arbitrarily, 0 means that the relay is closed after 0.5 seconds, and 999 means that the relay is always closed until the number allowed is called. The current status of the device can be queried through SMS commands, and you can regularly upload the current status of the device to the first user via SMS., Manufacturer: ZXZZAS