In a HART-enabled 4-20 mA loop, what represents the process variable (PV), and how is the digital HART data transmitted?

• A. The PV is represented by the analog 4-20 mA current, and the HART data is carried by a modulated signal superimposed on that current.
• B. The PV is represented by a digital value sent over the bus, while HART data uses a separate dedicated line.
• C. The PV is represented by a voltage level; HART data uses a separate power supply for data.
• D. The PV is represented by a sensor resistance; HART data uses frequency shift keying on the loop.

Answer: (A)