The use of the HART multiplexer in combination with a HART termination board or pac-Carrier is a practical means of enabling HART communication between field devices and a HART Asset Management System. The devices enable HART signals to be coupled and decoupled. The 4–20 mA signals are linked to the HART termination board and the HART multiplexer communicates with the individual field devices consecutively. Communication to the HART Asset Management System is performed via RS-485. The signal can be converted to RS-232 using the fieldbus isolating repeater. Special transducers are available as accessories for conversion to an Ethernet signal. CommDTM is used for integration into FDT software.