UNIVERSAL OPERATOR STATION MODULE FOR A DISTRIBUTED PROCESS CONTROL SYSTEM

A module of a distributed process control system has a prior art kernel submodule, a peripheral submodule, and an interface circuit to provide for communications between the two submodules. The kernel submodule communicates with the interface circuit over a module BUS which includes a data BUS and an address BUS. The peripheral submodule communicates with the interface circuit over a peripheral component interface (PCI) BUS, a single thirty two bit BUS which is incompatible with the module BUS. The interface circuit permits such communications between the two submodules without requiring any hardware or software changes to the kernel submodule and the module BUS, nor to components of the peripheral submodule or its PCI BUS. The interface circuit includes interface registers, a control circuit which determines which submodule is permitted to write or read data and/or address into or from a given register of the interface registers. Input circuits controlled by control signals produced by the control circuit determines the source of the data and/or addresses written into a given register. An output circuit under the control of the control circuit determines the BUS over which the contents of a given register are transmitted to the addressed submodule.