What is the purpose of a signal conditioner in a DDC system?

• A. To convert, scale, filter, or isolate sensor signals so the controller can read them accurately.
• B. To provide power to the sensors.
• C. To encrypt data.
• D. To replace faulty sensors.

Answer: (A)

The signal conditioner’s job is to prepare raw sensor signals so the DDC controller can read them accurately. It handles converting the sensor’s output into a form the controller expects, scaling it to the controller’s input range, filtering out noise, and providing isolation to protect the controller from faults or ground loops. Sensors can produce a variety of signals—voltage, current, different ranges, or noisy data—and the conditioner makes these compatible and stable for precise ADC readings. This reliability is essential for accurate control decisions in the DDC system. It’s not about powering sensors, encrypting data, or replacing faulty sensors.