A signal processing board including a resource board substrate, an external interface on the board substrate, adapted to receive signals for processing, at least one slot adapted to receive a plug-in module with at least one processor thereon and an interface unit adapted to at least participate in converting signals exchanged between the external interface and a processor on a module received by the slot, between a format of signals received by the external interface and a signal format of the processor. The interface unit is suitable to at least participate in the conversion for a plurality of types of processors that differ in the format in which they transmit or receive signals.