Hart Communicator : The Hart Communicator with its high range of communication is one of the most popular protocols available today.
There are two main operational modes of these types of protocols
- Point To Point, where the specified signal at one point ranges from 4 to 20 mA. The signals are often digitally send, and the polling address of the instrument is set to zero marks.
- Multi Drop, where the analog loop current is normally fixed to 4 mA. This allows several instruments to be used in a single loop.