The changes in social environment, such as globalization of enterprise activities, depletion of natural resources, and eco-oriented movement will affect the structure of mass production. Control systems must be prepared with flexibility and scalability in both size and function to adjust to the changes.

To configure a compact, low-power medium attachment unit for field buses, i.e., a fieldbus MAU, an IC comprising a power generator, transmitter/receiver and other functions is needed. While we at Yokogawa had already developed a fieldbus MAU IC, we have now developed another MAU IC that includes large-scale design changes made mainly to comply with the low-power signaling requirements of the fieldbus specifications. 

Progress in digital signal processing and network technologies has enabled advanced functions which cannot be achieved by traditional field devices with 4-20 mA signal, to be implemented on field devices. Standardization of international fieldbus specifications, notably the FOUNDATION™ Fieldbus, has enabled users to build optimum field networks comprised of freely chosen field devices from various device vendors.