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Why is a 250-ohm resistor needed when using a HART communicator to modify parameters such as the transmitter’s range? If it’s not connected, it won’t work, right?
Whether a resistor needs to be connected depends on the device itself; if the device has sufficient internal resistance, no resistor is needed, but if not, one is required. Series resistance is used to improve the mathematical communication capabilities by raising the potential; it is widely applied in areas such as coaxial cable communication and serial communication. Communication networks generally have terminal resistance, and their functions are all the same.
I’ve used it; it can communicate without the need for series resistors
Learn* it a bit, thanks:lol
The key is whether a load is present; communication is possible with a load, while a resistor needs to be connected in the absence of a load
Without a load, a 250-ohm resistor needs to be connected in series, which acts as a load and generates a 4-20mA signal
Is it called loop terminal resistance? It needs to be present in the power supply circuit; if it’s there, then no issue is needed, but if it’s not present, communication will not be possible, and it’s necessary to add one manually
Do not mislead. The purpose of series resistance is to prevent the HART communicator signal from being \"short-circuited\" by low resistances such as those in the power supply.
Nonsense! Whether to connect a resistor depends on the circuit!
I never use them in series; what’s the problem? They’re used in the same way – it’s just the wiring method that’s different.