The alarm client for the Process Historian is a PCS 7/WinCC add-on that enables convenient viewing of archived messages and alarms in the SIMATIC Process Historian as well as statistical evaluation. The use of the alarm client does not affect production.

Messages can be selected in detail in order to simplify analysis. These selections can be saved in order to perform repeated message queries with the same selection criteria.

The following options are available:

• Time period
• Message source
• Message type (operator message, process control message, etc.)

Pre-defined message evaluations are also available. These include:

• Analysis of the most frequent messages in query period
• Temporal distribution in query period
• Detection of recurring messages

The alarm client shown above can also be used for SIMATIC PCS 7 plants with PCS 7 V6 and V7 versions (these are not supported by the SIMATIC Process Historian) and for other process control systems with OPC A&E interfaces. However, additional interfaces are still required for detecting messages. Similarly, versions can be used when dealing with very large plants with numerous messages and simultaneous increased performance requirements for alarm evaluation.