Used as a complement to the powerful system diagnostics built-in to the SIMATIC S7 Programmable Controllers, S7-PDIAG is used to configure process diagnostics during the creation of the project with the standard programming languages. S7-PDIAG allows you to monitor an operational process, and detect / report faults (i.e., limit switch failure, motor overload) to a HMI package such as SIMATIC WinCC Flexible or WinCC. Messaging and annunciation screens are pre-built as part of the ProAgent option for SIMATIC HMI.