Redundant server systems for increased plant availability

Siemens Industry Automation Division has new software for configuring redundant OPC UA servers (Openness, Productivity & Collaboration, Unified Architecture). The S7 OPC Redundancy application allows the design of redundant server systems for fail-safe connection of HMI devices within Industrial Ethernet or PROFIBUS networks. OPC is a standardised and open interface for connecting Windows applications using various protocols such as S7-communication, Profinet and SNMP. The extended development version, OPC UA, additionally provides security and redundancy functions, for example.

Within a redundant server structure, a backup server immediately assumes the functions of the failed OPC UA server in the event of a power outage or system failure. In this way, connected clients such as HMI devices can access the central data and remain operational without interruption. The new Siemens software thus increases the availability of automation data to HMI systems. In normal operation, the clients are distributed evenly across all connected servers, providing improved utilization of IT resources.

PCs with the Windows Server operating system, Simatic Net S7 basic software, and the new S7 OPC Redundancy application are required to establish a redundant OPC UA server system. The OPC UA server is synchronized using high-performance Industrial Ethernet access points with a bandwidth of 10, 100 or 1,000 Mbit/s. No additional wiring is required. The connected OPC clients require the appropriate OPC UA support for communication. Existing standard OPC UA clients with reconnect functionality in accordance with the OPC UA specification can continue to be used.