Connection of SIMATIC HMI to the S7-1500R/H

Hello SIOS forum community.

The connection of HMI systems to redundant controllers usually requires a special connection handling in the HMI, e.g. the monitoring of the connection and the variation of the partner address at runtime via user scripts. In the context of S7-400H, the communication package SIMATIC NET Redconnect is also available for PC-based HMI systems, which organizes the connection switchover between both H subsystems and hides the redundant character of the communication partner for the HMI system.

In connection with S7-1500R/H controllers a new and simple method is available to solve this task. The two CPUs of a S7-1500R/H station can be assigned a common IP address in addition to the respective individual IP addresses for each interface during project planning. This so-called "System IP" represents the entire station and is operated by the "Primary CPU*". A communication partner such as an HMI system can thus connect to the system IP and therefore does not need to bring along any specific capabilities or incur any expenses in order to operate a connection redundantly.

This technology forms a perfect combination in conjunction with the operation of the HMI on the MRP ring on the x1 interface of the R/H CPUs, since here the line path to the primary CPU is also redundant at all times.

(*the CPU that has just assumed the leading role in the CPU pair at runtime is referred to as the "Primary CPU").

When connecting an HMI to the x2 interface, which does not have an onboard switch and thus cannot be directly integrated into an MRP ring, at least a small part of the connection path to the Primary CPU remains non-redundant (e.g. the patch cable to the next switch). If this restriction should not be tolerable, a connection switchover via user script would then have to be implemented here again*.

(*see Connecting SIMATIC HMI operator panel to SIMATIC S7-1500R/H)

Best regards,

SIMATIC International Technical Support Hub