HCS-8300 dual main unit hot spare is a disaster protective structure. Besides the Congress Main Unit, user can set another Congress Main Unit as backup Congress Main Unit and connect it to the system. If the Congress Main Unit breaks down during the conference, the backup Congress Main Unit substitutes the Congress Main Unit and system software will connect to backup Congress Main Unit automatically, ensuring consistency of the conference. HCS-8300 application software is comprehensive, reliable and user-friendly. But it is also an easy care software system which helps the operator to manage the conference efficiently from the very beginning of a meeting until the post-meeting work. With the PC installed HCS-8300 application software connected into the Fully Digital Conference System (FDCS), the operator can manage all aspects of the conference centrally. The operation turns out to be easy and efficient.