A specialized relay is required because PLC electronics are designed for logic processing, not for directly switching high-power equipment like motors or heating elements. If you have full control of the system and its design, then I wouldn't bother with relays unless they're electrically necessary (or if a customer. A Programmable Logic Controller (PLC) acts as the “brain” within modern industrial machinery, executing programmed logic to manage automated processes. PLCs operate using low-voltage electrical signals, typically 5 or 24 volts direct current, to protect sensitive electronic components. It's often appropriate to use these more complicated (and capable) options and remove or forgo. Relays are used in PLCs to control the flow of electricity to different devices like motors and lights. They act as switches, allowing the PLC to manage high-power devices with low-power signals. This is essential for automation systems where precise control is needed.