In the realm of industrial automation, the integration and communication between devices across different networks are crucial for efficient operations. Traditionally achieving connectivity between internal and external networks required additional hardware, such as NAT routers. However, the introduction of IP forwarding functionality in the Simatic S7-1500 PLCs has revolutionised how we approach network configurations and offers a more streamlined and cost-effective solution.

In this case study we’ll show you how we addressed this challenge.

Background

Siemens released the firmware update V2.8. This enabled IP forwarding on Simatic S7-1500 PLCs for CPUs with at least two Ethernet interfaces. IP forwarding allows these devices to forward IP packets between two connected IP subnets. This eliminates the need for external routing hardware in certain configurations.

Challenge

Before the implementation of IP forwarding, connecting devices like the KTP900F HMI on an internal network to an external network—for purposes such as accessing a Simatic Logon Active Directory, external data archiving, or synchronising with an NTP server—required a Scalance NAT router. This not only added complexity to the network setup but also increased costs due to the need for additional hardware and a larger enclosure to accommodate the setup.

Simatic S7-1500 IP Forwarding Solution and Implementation

The potential of IP forwarding was first tested in August 2020 on the Boehringer Ingelheim project. Despite the successful test, the external network connection was not implemented due to the client’s decision. The breakthrough came with another of our pharmaceutical end users, Amgen project in August 2023. The client was presented with the IP forwarding solution, which was readily accepted and implemented.

Results

The adoption of IP forwarding for the Amgen project demonstrated significant advantages:

• Reduced Complexity: Eliminating the need for an additional NAT router simplified the network configuration. This makes it easier to manage and maintain
• Cost Savings: We avoided the direct cost of purchasing NAT routers and the indirect cost of acquiring larger enclosures for the hardware
• Streamlined Configuration: With IP forwarding, we configured the devices directly in the TIA Portal. Therefore enhancing the efficiency of the setup process.

Conclusion

The introduction of IP forwarding in Simatic S7-1500 PLCs represents a significant step forward in network management within industrial settings. By enabling direct communication between internal and external networks without additional hardware, Siemens has provided a solution that not only simplifies the configuration process but also results in tangible cost savings for clients. The successful implementation in the Amgen project serves as a testament to the benefits of this feature. This highlighting its potential for widespread adoption in various industrial applications.