What serves as the interface between field devices and ladder logic in a PLC?

The interface between field devices and ladder logic in a PLC is the input/output systems. These systems are essential components of a PLC architecture as they facilitate the communication and data transfer between the external devices in the field, such as sensors and actuators, and the internal processing elements of the PLC.

Input/output systems manage the signals coming from field devices and convert these signals into a form that the PLC can process. For instance, input signals from sensors are translated into binary signals that the PLC can understand, and output signals from the PLC are sent back to actuators or other devices based on the logic defined in the ladder diagram.

This interaction is crucial for real-time automation processes, ensuring that the PLC can receive feedback from the field and execute commands to control equipment accordingly. Without the input/output systems, there would be no effective means of communication between the physical devices in the field and the control logic implemented in the PLC.