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Moxa Switches Bring Legacy Devices to PRP/HSR Networks

PT-7728-PTP switches implement PRP/HSR zero time recovery and RSTP Grouping for legacy migration.

Brea, California, October 12, 2016—Moxa is launching the world's first PRP/HSR rackmount switch. The PT-7728-PTP is a 24+4G modular Ethernet bridge that enables zero-time failover and significant interoperability between standard PRP, HSR, and RSTP protocols to achieve the highest network availability and deployment flexibility for time-critical applications.

Full Gigabit PRP/HSR Connectivity
The modular PT-7728-PTP switch uses either a 4G copper or fiber module to implement zero packet loss and zero-time recovery in compliance with Parallel Redundancy Protocol (PRP) and High-availability Seamless Redundancy (HSR) protocols, both defined in the IEC 62439-3 standard.  

Flexible Migration
The PT-7728-PTP provides 24+4G modular connectivity that allows legacy and single attached node (SAN) devices to get connected to PRP/HSR-based networks over copper, optical fiber, or a mixture of the two.

RSTP Grouping
Furthermore, the PT-7728-PTP features RSTP Grouping, a patent-pending technology, which enables multiple couplings of RSTP rings to HSR-based networks. A pair of PT-7728-PTP switches can migrate more than a thousand RSTP devices to HSR-based networks—far more than the maximum of 40 hops allowed in a typical RSTP ring.

Cost Advantages
The migration capabilities of this HSR-and-RSTP-hybrid topology are extremely beneficial for substations that want to add PRP/HSR segments to their legacy RSTP-based networks to improve network performance and reliability. The PT-7728-PTP extends the lifetime of legacy devices and network infrastructures for retrofit applications, and it also improves network availability as defined in the IEC 61850-3 standard for mission-critical applications.

Proven Interoperability
The switch demonstrated its redundancy and interoperability capabilities in the 2015 PRP/HSR Interoperability Test, conducted by UCAIug," said Jun Chuang, product manager of Moxa's Power Communication Systems. "The PT-7728-PTP and Moxa's PT-G503 RedBox were the only DUTs (devices under testing) that provided dual connections between PRP/HSR and RSTP network segments during the test."

Comprehensive Product Lines
Jun added, "PRP/HSR standards define the best network availability for the most critical applications. However, customers are also concerned about the complexity of a device, its costs, and the increased traffic load on their network. Moxa provides a full range of PRP/HSR products, including high-port density modular switches, compact DIN-rail RedBoxes, embedded modules, and computer management platforms, to help customers construct or retrofit their network infrastructures as required for time-sensitive and mission-critical applications."


  • IEC 61850-3, IEEE 1613 (power substations) compliant
  • Implements IEC 62439-3 compliant PRP/HSR zero time redundancy
  • RSTP Grouping with multiple HSR and RSTP couplings
  • 24+4G switching
  • Hardware-based IEEE 1588v2 PTP supported
  • Isolated redundant power inputs
  • -40 to 85°C operating temperature range
  • Built-in MMS data modeling for SCADA systems in power applications


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About Moxa: Your Trusted Partner in Automation

Moxa is a leading provider of edge connectivity, industrial computing, and network infrastructure solutions for enabling connectivity for the Industrial Internet of Things. With over 30 years of industry experience, Moxa has connected more than 50 million devices worldwide and has a distribution and service network that reaches customers in more than 70 countries. Moxa delivers lasting business value by empowering industry with reliable networks and sincere service for industrial communications infrastructures. Information about Moxa’s solutions is available at www.moxa.com.