In the context of PLCs, what do I/O modules do?

I/O modules play a crucial role in the functionality of Programmable Logic Controllers (PLCs) by acting as the interface between the PLC and the external devices, which include sensors and actuators. These modules are essential for monitoring inputs from the physical environment and sending commands to control outputs.

When a sensor detects a physical quantity, such as temperature or pressure, it sends this data to the PLC via the I/O module. The PLC processes this information according to the programmed control logic and, based on that logic, sends commands through the I/O module to actuate devices like motors, valves, or relays. This bidirectional communication is vital for automation processes, as it allows real-time interaction between the PLC and the equipment it controls.

The significance of I/O modules extends to their flexibility and configurability. Different types of I/O modules can be used to handle different types of signals (e.g., digital or analog), which increases the versatility of the PLC in various applications.