An interface module is operatively coupled to a Fieldbus process control
network and a Modbus process control network to facilitate the exchange
of process control information between the networks. The interface module
stores a register map database in which the process control parameters of
the function blocks in the field devices of the Fieldbus process control
network are mapped to register numbers of the Modbus process control
network. Once the Fieldbus process control parameters are mapped to the
Modbus registers, the interface module is adapted to transmit request
messages on the Fieldbus process control network to the Fieldbus field
devices for the current values of the process control parameters, receive
response messages from the Fieldbus field devices, and store the current
values of the process control parameters in the register map database.