What interface allows users to configure and monitor a PLC system?

The Human-Machine Interface (HMI) is the correct choice for configuring and monitoring a Programmable Logic Controller (PLC) system. HMIs serve as the bridge between operators and the machinery they control, providing a visual representation of the system's status and facilitating user interactions. This interface enables users to input commands, view real-time data, and receive feedback from the PLC, making it essential for effective monitoring and management of automated processes.

Using an HMI can greatly enhance operational efficiency because it synthesizes complex data into an understandable format, allowing for easier diagnostics, troubleshooting, and configuration adjustments. The ability to visualize operational metrics and performance indicators in a user-friendly manner is a critical feature of HMIs, which supports users in making informed decisions quickly.

Other interfaces like a web interface could potentially be used to interact with a PLC but are typically not the primary method for direct configuration and monitoring. Control panels focus more on physical controls than data visualization or configurability through software, and while a supervisor interface could imply a higher-level management view, it's not a standard term used specifically in the context of PLC configuration and monitoring like HMI. Therefore, the Human-Machine Interface stands out as the most appropriate and conventional choice for this application.