Communication system and method between serial boards

The invention relates to a serial inter-board communication system, which comprises: a main controller and a service unit, wherein said main controller comprises at least one independent band-external manage channel MHW; each MHW is connected to at least one service unit. The invention also provides a serial inter-board communication method. The invention uses independent MHW with several service units, to support mixed transmission hardware state and manage report, with less signal needed by back board; and the cost of each module is lower, the transmission speed can meet band-external manage demand, and it separates the band-internal and band-external managements to improve the safety of system.