In configuring a passive transmitter, you connect it to the power supply in what way?

In configuring a passive transmitter, you connect it to the power supply in what way?

• A. Passive transmitter to active loop power supply.
• B. Active transmitter to passive input.
• C. Passive transmitter to passive input.
• D. Active transmitter to active loop supply.

Answer: (A)

In a 4–20 mA loop, a passive transmitter does not supply its own power. It relies on the loop power source to energize its electronics, so you connect it to an active loop power supply that provides the loop current. The transmitter sits in series with that loop and modulates the current to represent the measured value, drawing power from the supply rather than generating it itself. Connecting a passive transmitter to a passive input would leave it without a power source, and using an active transmitter would imply it has its own power source, which isn’t the case here.

In a 4–20 mA loop, a passive transmitter does not supply its own power. It relies on the loop power source to energize its electronics, so you connect it to an active loop power supply that provides the loop current. The transmitter sits in series with that loop and modulates the current to represent the measured value, drawing power from the supply rather than generating it itself. Connecting a passive transmitter to a passive input would leave it without a power source, and using an active transmitter would imply it has its own power source, which isn’t the case here.