PLC Inputs and Outputs 231

PLC Inputs and Outputs provides an overview of the main types of input/output modules and input/output devices, their primary functions, and their roles in a PLC process. In a PLC system, the input/output modules are connected to the input/output devices that send and receive electrical signals throughout a process. Input/output modules may operate using alternating current (AC) or direct current (DC), and may be analog or discrete, depending on the type of electrical signals they process. Having a foundational knowledge of the functions and capabilities of the input/output modules in a PLC helps users understand basic PLC operation. Being aware of the different types of input/output modules and their capabilities is essential to working with PLC systems.