Substation Communication Infrastructure

Communication has always played a critical role in power systems and will become even more critical when it comes to implementing an end-to-end and two-way open communication grid infrastructure. Belden plays a key role in PT&D by transforming the more intelligent grid with innovative products, solutions and services. As such, Belden is committed to providing a highly reliable secure, and standard based communication infrastructure.

Grid reliability for maximum uptime

Strong, long-term strong partnerships with the leading companies in the power market have enabled Belden to develop innovative substation-specific communication network, cable and connectivity solutions that help electric utilities react to the pressure to ensure their grids remain reliable over a wide range of operating conditions and to extend the operating life of key assets. Belden ensures that a highly reliable communication network infrastructure is available.

Compliance enhances efficiency

Belden products are designed to meet the Ethernet based IEC 61850 standard for substation automation and protection, IEC 62351 for Data and Communication Security, IEEE 1588 compliance for precision time synchronization and IEC-62439 standard redundancy protocols (PRP, HSR) and these represent only a few of the many key standards. This compliance helps electric utilities to enhance efficiency by supporting interoperability, free architecture and uninterrupted two-way open data communication of the substations.

Cyber Network protection increases availability and safety

Substation communication networks represent mission-critical infrastructure. Security threats generally consist of attacks against assets or are caused by unintentional faulty operation of the system. Cyber data security is a vital element of a substation system’s reliability. Cyber security maintains the availability and safety of control systems and reduces operational expenses in substations. Belden provides state-of-the-art security for substation automation networks and offers a full range of unique products and solutions that meet even the most demanding security requirements.

Fiber Optic based process bus reduces costs

Fiber optic cabling based process bus is the first step in reducing the amount of copper wiring in the digital switchyard. Instead of several kilometers of copper in one HV substation only a few hundred meters of fiber needs to be installed. In a critical situation such as a lightning strike, fiber guarantees 100% availability of the communication network infrastructure whenever fast reaction time is required.

Designed to meet the most demanding substation requirements

Hirschmann™ substation products are designed to meet all environmental conditions, EMC requirements and functionality required at all levels of substation automation.

Tailored to meet your needs

Leading substation automation vendors rely on Belden products which have been embedded thoroughly in their automation systems, where they help to maximize the performance of the system through customized solutions.

Intensive project pre- and after sales support

We are able to support, deliver and maintain our products anywhere in the world. The Belden Competence Center and a strong System Integrator Platform plan, support the design and installation of complete communication networks for greenfield substations or complete substation upgrades.

Meeting or exceeding the highest quality standards

“Made in Germany”: Hirschmann™ quality is based on a three phase process, starting with a strong integrated R&D Process using an integrated approach such as V-Model, followed by most intensive product qualification programs and includes finally a 100% production testing before shipping to the customer. All the Belden processes are implemented to go considerably further than the industry-independent ISO 9001:2008 standard. Hirschmann™ for example exceeds IRIS standard requirements and holds IRIS V 0.2 certification.

Driving innovation in the power market

Belden delivers constant innovation in areas such as embedding Ethernet interfaces into IEDs, and plays a leading role in specifying and implementing new redundancy protocols such as PRP / HSR. The company is a pioneer in time synchronization as well as in defining new security methods to protect automation systems.

Sharing knowledge within international PT&D standard committees

Through its Hirschmann™ brand, Belden is actively involved in many Power Transmission & Distribution standardization organizations. The company is an active member of IEC TC57, IEC SC65C, IEEE1588, IEEE PSRC as well as in IEEE802 LAN/MAN Standards Committee.

Ethernet based IEC61850 is becoming the core standard in power systems

IEC61850 is a future-proofed standard for safe investment. It meets utilities’ requirements to combine products from a variety of manufacturers for long term system exchangeability of equipment and expandability. The standard is being applied increasingly in transmission substation automation and will be implemented down to substation distribution applications.

Increasing security requirements for IP based substation communication

A digitized grid will bring major changes to the way electricity is generated, transmitted, distributed and consumed. Communication among various automation components is critical and requires open communication systems, often based on Ethernet and Internet. These systems are much more vulnerable to cyber attack. In addition, utilities must meet regulatory requirements. Most cyber security regulations are just reaching the point of implementation in the utility industry; so many utilities are struggling with basic understanding and proper paths to compliance.

Implementation of IEC 61850 drives a shift from copper to fiber cabling

The bay principle, where control devices and relay equipment are located in the switchyard, will move into the central control room of the substation connected by fiber optics to cabinets close to the primary equipment. This results in eliminated copper connections between the switchgear equipment and metering, protection and control devices. IEE 61850 allows process devices as IEDs to be mounted directly onto the primary equipment, connected via fiber optics to the control room.

Uninterrupted data communication at process level

Data flow needs to be guaranteed to enable electricity to flow from power generation to consumers. Therefore using Ethernet to link the field – level transformer stations of a power supply grid calls for critical mission data communication. The IEC-standard redundancy protocols (PRP, HSR) can guarantee for the first time uninterrupted communication in power systems in even the harshest of environments.

What differentiates the technologies MRP vs RSTP?

The Media Redundancy Protocol, MRP, was designed to address the needs of industrial applications. This protocol is described in Standard IEC 62439, the industry standard for high availability networks. MRP is exclusively defined for ring networks, however, it guarantees deterministic fault recover time behavior.

Depending on the set of parameters used, the recovery time in a failure situation can be guaranteed to be less than 500ms, 200ms or even 10ms. Configuration of a MRP ring is very simple, only a redundancy manager has to be defined.

RSTP, the Rapid Spanning Tree Protocol is an optimised Version of STP and is defined by IEEE 802.1D. RSTP implementation works with different kinds of topologies, e.g. rings or meshed networks, even in very large networks. However RSTP does not guarantee deterministic recovery time behavior. The recovery times depend on where in the network the failure happens and on the individual implementation.

Because of this there are several attempts to optimize RSTP by limiting the use to ring topologies and the use of predefined parameters. Based on these optimizations it is possible today to demonstrate fault recovery times the size of 100 milliseconds or even below. The configuration effort for RSTP is medium due to the different options such as root switch, priority, etc.

How many switches can be put in an MRP or RSTP ring?

MRP: 50+. Switches based on ring topology. Recovery time is almost independent of the number of switches in the ring

RSTP: up to 40 Switches for any type of topology. Because RSTP works in a hop-by-hop principle, recovery time will almost linearly increase with the number of switches in the ring.

What are the recovery times of HSR (best case and worst case)?

There is no best or worst case recovery time for HSR, since there is no recovery time at all. The network recovery time from no fault to a single fault in a ring will always be zero. Also, the repair operation from one fault to no fault is also with zero switchover time.

HSR, as MRP or RSTP in ring configuration, can only sustain one fault in the ring network. This is due to the physical topology, not due to the redundancy protocol. Rings that are coupled via Quad Boxes do not share the same redundancy domain. Therefore, each individual ring can sustain a single fault.

Are HSR/PRP standardized technologies or are they proprietary?

Both HSR and PRP are specified in the International Standard IEC 62439-3. HSR and PRP are therefore standardized and not proprietary technologies.

If HSR and PRP are superior to MRP or RSTP, why should I continue to use them? Why shouldn’t I switch over to HSR/PRP completely?

While HSR and PRP are superior to MRP or RSTP in terms of reconfiguration performance, there are also drawbacks to the technology:

  • PRP: Requires a complete network infrastructure for both networks, which usually means double the costs for network equipment.
  • PRP and HSR: For both PRP and HSR, hardware support through FPGAs or ASICs is required, leading to higher device costs.
  • HSR: Compared to an MRP ring or RSTP in ring configuration, HSR carries only 50% of the traffic (available bandwidth is halved due to doubled frame transmission).

Where seamless redundancy is not explicitly needed, the use of MRP (with SubRings) or RSTP technology may be more cost-effective than HSR/PRP. But where the application requirements justify the additional costs, PRP/HSR can be utilized.

If HSR/PRP is a standardized technology, why should I buy an HSR/PRP device from Hirschmann? Other vendors will provide the same redundancy functionality?

There are several answers to this question. It is true that the technology is standardized, but there are several key factors why a customer should buy a Hirschmann HSR/PRP device:

  • Hirschmann was instrumental in the development of the PRP/HSR standard. With Hirschmann products, a customer can be absolutely sure that the device will satisfy every requirement HSR/PRP was designed to accommodate and that, thanks to our detailed insight knowledge, the implementation is of high performance and absolutely 100% standard conformant.
  • A high performance redundancy is almost useless without proper monitoring and fault detection. Hirschmann HSR/PRP switch products will be integrated into our state-of-the-art SCADA tool Industrial HiVision, which adds up to a combined redundancy and network solution that no competitor can match.

What are the typical application fields of PRP and HSR?

HSR and PRP were conceived for use in IEC 61850 substation automation, where network reconfiguration times cannot be tolerated, especially on the process bus with sampled values traffic. However, PRP/HSR can also be used in factory automation, especially as redundancy solutions for motion control applications.

In short, PRP/HSR can be used anywhere when only very low to zero network recovery times can be tolerated. This is especially true in time synchronized networks, e.g. with IEEE 1588v2. HSR in particular with its ring structure and cut-through switching, can also provide very low end-to-end latency on ring networks.

How many HSR ring devices are supported?

The total number of HSR devices in one ring should be limited to 50. This is mainly to reduce the latency in the ring. For very time-critical applications it may be necessary to limit the number of devices even to a smaller number. Another limitation for the number of devices in a ring can be the size of the duplicate detection table inside the device. This is dependent on the implementation.

Are HSR and PRP future-proof technologies? What is the technological outlook?

The IEC standard (IEC 62439-3) for HSR and PRP is now stable and the feasibility of the technology has been shown. HSR and PRP are highly future-proof thanks to the direct integration into the IEC 61850 standard and the acceptance of all major energy automation companies. HSR/PRP technology is expected to be successful in other application fields as well, in particular factory automation. The technology is scalable in line speed (Gigabit speed is scheduled as future improvement to the standard) and can be flexibly adapted to incorporate other technologies, e.g. 1588v2 time synchronization.

Case Studies


  • MMS Server ReadyHirschmann™ Software Release 8.0 offers a host of special functions such as an integrated IEC61850 (MMS) server for seamless integration into data networks for power generation and distribution.
  • RSPL-LiteRSPL switches offer the highest level of security and comprehensive diagnostic functionality.
  • RSP SwitchFor the first time, uninterupted data communication networks with PRP, HRS can be built with Hirschmann™ products. (PDF)

Hirschmann RSP Switches Wins 2013 Engineers' Choice Awards

In the category “Network Integration – Ethernet Hardware” Hirschmann’s RSP Managed Switches are the Control Engineering 2013 Engineers' Choice Award winner.

Smart Grid Companies to Watch in 2013

Belden is voted as one of the top 13 Smart Grid Companies to Watch in 2013.