Expert’s answer: HART without 4-20 mA?
No, you can’t have a HART without 4-20 mA. The HART network depends on analog communication. You can read more about the protocol here.
When you have a multidrop network, the current stays in 4 mA. Thus, you might say that you don’t have the 4-20 mA modulation, because the current stays at 4 mA and the process information comes from the HART communication.
With that in mind, you have other HART protocols that technically don’t have 4-20 mA. For example, wirelessHART and HART-IP. Both protocols are HART, but they provide digital communication based on wireless and Ethernet.
For more information, please check the list below:
Other resources that might interest you
I have an AMS suite device manager, and I would like to know if can I use the Viator Bluetooth with my software? Do you know about that?
Display or handheld configuration
I have a question about HART communicators. Can you help? When we have a local configuration, when do we use the HART communicator?
HART device power supply
I have another question about HART communicators and devices. The question is: should we feed 24 VDC to a HART device only through a PLC/DCS or can we do it with an external power supply?
Should I always have a 250-ohm resistor to use the handheld communicator with a HART device?