What is the main purpose of using limit switches in PLC applications?

Limit switches are primarily utilized in PLC (Programmable Logic Controller) applications to detect physical limits of motion. They are designed to sense the position of mechanical components, such as the end points of a moving part, like doors or conveyor belts. When these moving components reach a specific position, the limit switch activates or deactivates its circuit, sending a signal to the PLC to perform a predefined action.

This functionality is critical in automation systems to ensure safety, prevent mechanical damage, and enable precise control of machinery. For example, in a conveyor system, limit switches can indicate when an item has reached the end of the conveyor, prompting the system to stop or redirect motion. Therefore, the main purpose of limit switches is to provide feedback on the position of moving parts, which is vital for effective operation and control in various applications.