PLC-driven alarming

When a PLC and an HMI exist in the same project, common alarm classes can be configured for use in both devices.

Using supervisions and the ProDiag function block, the PLC can drive alarms to the HMI without having to configure HMI alarms in the HMI itself. One of the biggest benefits of using PLC-driven alarming is that the alarm resides in the function block associated with a supervision. This means that if the function block is standardized in a library, every project that uses the function block will be able to generate the same alarm automatically.

Supervisions can easily be created for any variable that is stored in a data block or as a PLC tag:

Figure 12.23 – Creating a supervision

In the Supervision column, right-click and choose Add new supervision. The properties window at the bottom of the screen opens on the Supervisions tab.

Note

TIA Portal will automatically create a global ProDiag function block and an associated...