Analog I/O modules can be configured to sense either voltage or current.

• A. True
• B. False
• C. Only voltage
• D. Only current

Answer: (A)

The main idea is that many analog input modules are designed to handle two types of sensor signals: voltage and current. They can be configured so a channel interprets the incoming signal as a voltage within a specified range (for example 0–10 V) or as a current within a range (such as 4–20 mA). When sensing current, the module uses a burden resistor to convert that current into a voltage that the ADC can read, and then applies the appropriate scaling to produce the correct process value. Because of this flexibility, the statement is true: the analog I/O module can be configured to sense either voltage or current. Some modules are fixed to one mode, but many are dual-mode, which is why this configuration capability is common.