A PLC can control a VSD using which type of input/output?

A Variable Speed Drive (VSD) is typically controlled by varying the frequency and voltage of the power supplied to an electric motor, which allows the motor to operate at different speeds. To effectively manage this operation, the programmable logic controller (PLC) often requires the ability to communicate specific control signals that dictate the desired speed and operational parameters of the VSD.

Discrete I/O refers to signals that are binary in nature, meaning they can only be on (true) or off (false). While discrete I/O can be used for basic operational controls, such as starting and stopping the VSD or enabling specific operational states, it does not cover the full control capabilities required for complex operations, typically reliant on analog signals.

In contrast, the correct choice demonstrates a fundamental requirement for controlling a VSD effectively. Analog I/O allows the PLC to send varying voltage or current levels to the VSD, which modulates the frequency and voltage being delivered to the motor. This capability is crucial for applications requiring precise speed control and fine-tuning of the motor's performance.

In practical scenarios, a PLC equipped with analog I/O can adjust the output signal dynamically based on feedback from sensors or other inputs, thereby facilitating more sophisticated control of the VSD and, by extension