OT networks form the backbone of modern automation systems, ensuring seamless communication between devices and controllers. These networks typically use star or line topologies, but protocols like EtherCAT and Sercos III may resemble ring topologies. Introducing network monitoring equipment into these live systems can disrupt operations, making it essential to implement non-intrusive traffic capture and analysis solutions.
In industrial environments, where processes are tightly coupled and timing is critical, adding new components can introduce delays or alter behavior, potentially hindering time-sensitive operations. This is where copper TAPs from Profitap prove invaluable. A copper TAP is a physical device intended to capture all traffic within a single network cable and provide separate TX/RX streams for those packets. They are invisible by design, meaning they will not introduce any additional delay or interfere with traffic. Therefore, they allow for seamless integration into existing networks without interfering with existing connections, ensuring the system's performance remains unaffected.
A significant advantage of copper TAPs is their ability to capture data in both directions separately. While this might seem an unnecessary complication for standard networks, in OT networks, the focus is often on monitoring traffic in a single direction—either to or from a device. This approach simplifies the capture process, as responses are generally not required for analysis, allowing engineers to focus on the most relevant data.
| TAP | IOTA |
|---|---|
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| • In-line traffic access. • Placed at potential points of interest. • Single purpose: copying traffic. |
• In-line or out-of-band. • Placed where active traffic capture and analysis is needed. • Designed for capturing, storing, and analyzing traffic. |
Another critical challenge in maintaining OT networks is diagnosing configuration issues. These can be timing-sensitive or even data-sensitive issues. By deploying multiple TAPs within a system, engineers can compare traffic streams directly. To collect this information, IOTA can help you. IOTA is a standalone capture and analysis tool designed to collect information and provide analysis dashboards for assessing the network situation. However, it is also a highly capable capture device with two independent capture ports. Together with the copper TAPs is where IOTA excels, allowing for a unified capture of multiple streams. With IOTA, simultaneous capture of TX streams enables comprehensive analysis, revealing issues related to configuration, delays, and data integration.
The graphic above shows how each data segment refers to a different system. Each device reads and writes into the same packets as they move through the network. If configuration issues occur, these are often hard to diagnose, as a direct comparison is difficult to achieve.
By applying a copper TAP in front and after the device and capturing only the TX stream from both TAPs with an IOTA, a congregated capture can be achieved, which allows for tracking those configuration issues quite easily.
Placement of copper TAPs
The effectiveness of using copper TAPs and IOTA devices depends significantly on their placement within the network. Here are the ideal positions for placement and the monitoring benefits they provide:
1. Directly after the PLC
This placement allows for complete control over all packets sent and received. During development, an IOTA can be placed instead of a copper TAP to ensure everything sent over the network is being seen. This is the primary analysis point for configuration issues, devices configured, and general timing issues.
Monitoring achievements:
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Control over all packets sent and received
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Analysis of configuration issues
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Monitoring of device configurations
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General timing issues
2. After the last configured device
This placement is different from the physical placement of that device as it may differ. Positioning a TAP after the last device that will be contacted in the cycle allows for monitoring cycle times, data integration, and network consistency. Combined with the TAP behind the PLC, this point ensures cycle time correctness, propagation delays, packet completeness, and all packets transmitted.
Monitoring achievements:
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Monitoring cycle times
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Integration of data
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Network consistency
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Cycle time correctness
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Propagation delays
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Packet completeness
3. Before and after a branch separates
This placement ensures that critical branches can be monitored and their timing can be tracked. It is essential to ensure that critical paths receive all correct information and required data.
Monitoring achievements:
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Monitoring critical branches
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Timing monitoring
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Ensuring critical paths receive correct information
4. Before and after a specific device
A TAP should be placed before and after specific devices that need to be monitored. Only by monitoring TX vs. TX or RX vs. RX can direct interference by the device be tracked.
Monitoring achievements:
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Monitoring specific devices
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Tracking direct interference by the device
Comprehensive monitoring and analysis
Integrating copper TAPs and IOTA into OT networks offers a robust, non-intrusive traffic capture and analysis solution. These tools ensure that critical communications remain uninterrupted while providing the necessary data to troubleshoot and optimize network performance. Leveraging these technologies is essential to maintaining efficient and reliable network operations for any professional working in industrial automation.
By strategically placing copper TAPs at key capture points in the network, engineers can achieve detailed insights into network performance and quickly identify and resolve issues. The combination of Profitap copper TAPs and IOTA’s powerful capture and analysis capabilities provides a comprehensive monitoring solution essential for maintaining and optimizing industrial Ethernet networks.
Conclusion
In conclusion, integrating physical TAPs and IOTA into industrial Ethernet networks offers an unparalleled approach to traffic capture and analysis. The strategic placement of these tools ensures minimal disruption to ongoing operations while providing the critical data needed for troubleshooting and optimization. For professionals in industrial automation, this methodology is indispensable for maintaining robust, efficient, and reliable network operations.
