In this paper, we propose an intelligent channelmultiplexed home intercom system based on Voice over IP (VoIP), which is different from traditional home intercom system. The transmissions of audio and video signal are both supported in the system. According to different functions, the system is mainly divided into two modules: VoIP module and master control module. VoIP module consists of driver, OS Kernel and application layer, which can guarantee multiple tasks to be processed at the same time and ensure the real-time response of system. To save channel resource, Micro Control Unit (MCU) is used to realize the channelmultiplexed function via the communication with VoIP processor. Therefore, to ensure the normal communication between VoIP module and master control module, we define communication command words based on RS232 protocol. The test and application results indicate that our system achieves the goal of channel-multiplexed audio and video transmission based on VoIP, and has high expansibility.

Dispatching automation system is the nerve center of power grid. When