What are the differences between 4-20mA, HART, and RS-485 signals in your flowmeters?

Answer: 4-20mA is the foundational analog signal widely used in process control. HART is an enhanced version that superimposes a digital signal on top of the 4-20mA analog loop, allowing for extra diagnostic data transmission without interfering with the analog value. RS-485, on the other hand, is a purely digital communication standard. Practically, 4-20mA and HART are ideal for point-to-point connections, whereas RS-485 is best suited for multi-device bus networks.