How Does Time Impact Our Life?

 I remember well the discussion on understanding and using UTC Time in IEC 61850 ... a very time consuming discussion. There are still discussions going on ... should UTC be replaced by something else?

Whatever format and scale you are using or inventing ... you will see problems over a longer period of use.

These days we see even cars may have crucial issues with processing of time:

Honda, Acura cars hit by Y2K22 bug that rolls back clocks to 2002:

The report starts with: "Honda and Acura cars have been hit with a Year 2022 bug, aka Y2K22, that resets the navigation system's clock to January 1st, 2002, with no way to change it."

True? Yes, it seems to be true.

A well known issue is related to the year 2038: Year 2038 problem

Many other time formatting and storage bugs!! 

Use the time you have in 2022 to spent more of it for or with your family, friends, ... stay safe in 2022!

Happy new year! 

Lesson learned: Don't expect that more automation, more programs, more smart phones, ... give you any additional time in your life! I guess they will consume a lot of your free time to find and fix bugs of many kinds ... 

Real-time Access to German Generation and Consumption of Electricity

You have real-time access to the German generation and consumption of electricity:




Click HERE for the real-time data access.

Update on OPC UA IEC 61850 Companion Specification

The OPC UA IEC 61850 Companion Specification of the OPC Foundation is focusing on gateways that are intended to be used to transfer information fully and accurately through gateways between devices that implement IEC 61850 or OPC UA respectively.

While IEC 61850 is focusing on electricity generation, transmission, distribution, distributed energy resources (DER), and consumption, OPC UA is dealing with non-electrical industrial process activities. It is clear that users require integration of the electrical aspects of a plant with non-electrical aspects.

The information models defined in IEC 61850 were focused during the late 90s on protection and automation of electric power systems. In the meantime the models provide a huge number logical nodes (e.g., STMP = Supervision of temperature with measurement, alarms and trips, or FPID = PID loop control) applicable in most non-electrical applications domains. The communication services (Reporting, Logging, GOOSE, Control, Setting Group Control, ...) are generic for any application domain.

OPC UA’s modelling capabilities is understood to make it possible to transfer data between different systems without losing the semantics of data. Thus the drafted companion specification document describes how IEC 61850 data can exchanged using OPC UA data modelling and services.

Click HERE for more information.

IEC TC 88 PT 25 is currently working on a technical specification: 

Wind turbines - IEC 61400-25-41: Communications for monitoring and control of wind power plants - Mapping to communication profile based on IEC 62541 (OPC UA)

Microsoft has provided an Open-Source OPC UA stack to OPC Foundation! 

The new OPC Foundation .NET reference stack, based on the new .NET Standard Library technology, was developed and optimized by Microsoft to serve as the complete platform-independent infrastructure, from the embedded world to the cloud. This new version is enabled on the following supported platforms: Various Linux distributions, iOS, Android, Windows 7, Windows 8, Windows 8.1, Windows 10, Windows Phone, HoloLens and the Azure cloud.

Click HERE for the press news from the OPC Foundation.

Click HERE for accessing the open source reference stack at Gidhub.

Brief comparison of IEC 61850 and OPC UA:
Standard? Yes for both in IEC.
Available since? IEC 61850 for some 15 years; OPC UA for a few years.
SCADA support? Yes for both.
Real-time support? Yes in IEC 61850; OPC UA is intended to run on TSN (IEEE 802).
Security? Yes for both (IEC 61850 refers to IEC 62351).
Semantic? IEC 61850 has huge, still growing list of models; OPC UA has not yet semantics.
Configuration Language? IEC 61850 has SCL (System Configuration Language); OPC UA has no.
Conformance testing? Yes for both.
Support: By many big and small companies.
Open Source Stack? Yes for IEC 61850 (http://libiec61850.com); yes for OPC UA (from Microsoft, see above).

TSN: Fieldbus Standardization - Another Way to Go

Fieldbus standardization has a very long history - resulting in tens of solutions in ONE single standard series IEC 61158. This has been discussed several times on this blog.
The latest decisions in the industrial automation domain could change the direction to go: To get one or two or three ... solutions - based on TSN (Time-sensitive Networking).
It took more than 25 years to implement in principle what I have written in a paper on Fieldbus and Ethernet. When I worked for Siemens Industry in the early 90s, I recommended to use native Ethernet instead of fieldbusses … now we write 2017 – 26 years later:
Click HERE for the paper “Bridging MAP to Ethernet” [PDF, 720 KB, 1991]
Click HERE for the paper “Fieldbus standardization: Another way to go” [PDF, 720 KB, 1991].

25 years of fieldbus wars are likely to end in the near future.
Even the Profibus International Users Group (PI) published the other day in the PI Profinews:
"TSN (Time-sensitive Networking) is a promising new IEEE technology for Ethernet that combines ... PI will expand PROFINET with the mechanisms of TSN in layer 2, retaining the application layer on the higher levels. This makes it possible to migrate the applications to the new technology simply and incrementally and to take advantage of the benefits of an open, globally standardized IT technology.”
Clicke HERE for the full announcement in the Profinews.

It's a pity that it took 25 years to understand that Ethernet is THE solution for the future.

TSN is just another link layer solution - what's about the upper layers? Huuch ... there is still the old fight of various groups that belief that their solution is the best!
PROFINET will keep their higher layers and add the option of OPC UA for higher automation levels to the cloud. So, they are recommending a compromise - which ends up in many higher layer solutions on TSN.

ABB, Bosch Rexroth, B&R, Cisco, GE, Kuka, NI, Schneider Electric, Belden/Hirschmann and Phoenix Contact are fighting for a SINGLE combination: TSN and OPC UA.

In the meantime we have - for more than 20 years - a SINGLE combination for the electric power (and energy) market: IEC 61850 with Ethernet and MMS (for client/server communication) supported by hundreds of vendors and users worldwide. AND: IEC 61850 has a huge basket of object models and a configuration language! What is being communicated through OPC UA TSN?

A finished solution (Ethernet/MMS some 25 years ago) is better than a perfect one that will never be accomplished - even not with TSN plus XX, YY, ZZ, ...!

This lets IEC 61850 look very good!

If you need your Profibus or Profinet data being communicated by IEC 61850, check HERE for Gateways.

Are You Looking for Authenticated Encrypted Time Signals?

GPS-based time signals could be less robust and reliable - this has been discussed in various forums. Electric power systems rely on time synchronization you can trust.

In a new US DOE project (TASQC - Timing Authentication Secured by Quantum Correlations) experts are planning to develop authenticated encrypted time signals that mitigate known vulnerabilities in GPS-based time. The project aims to:

• Develop and demonstrate a secure time distribution system using quantum-correlated signals over geographically wide area;
• Develop and demonstrate protocols for time-stamp authentication for data reported from power systems;
• Expand capability of the developed infrastructure for secure authentication of broadcast messages;
• Evaluate the system for cyber- and physical-vulnerabilities;
• Partner with industry to develop timing requirements for power systems and to refine design of system and protocols.

Phil Evans, Ph.D., TASQC Principle Investigator, Oak Ridge National Laboratory, respectfully requests your assistance for the TASQC project by both answering the questions in a brief survey, and distributing it amongst your colleagues in the electric power industry.

Beck IPC Offers New Very Powerful Embedded Platforms for Realtime Applications

Beck IPC (Wetzlas/Germany) is very successful in offering embedded platforms for many applications - including IEC 61850, IEC 60870-5-104, DNP3, ...
In order to offer a very powerful platform Beck IPC has developed two new SoM (System on Module): IPC@CHIP® SC1x5 and SC1x8 SoM

Some features:




Due to the compatible API, applications available for the SC143: IEC 61850, IEC 60870-5-101, (soon: DNP3), ... and many other applications, can easily be ported to the new powerful platform!

Click HERE for a two page brochure.
Click HERE for the latest documentation - search, e.g., for SC145

Training in Montreal (Canada): Mastering the complexity of IEC 61850

OPAL-RT TECHNOLOGIES invites you to the very crucial Training:

Mastering the complexity of IEC 61850

Adoption of the IEC 61850 standard in North America is slowly emerging for Transmission and Distribution markets, but an increasing number of implementations is expected, either through new installations or following cost-benefit assessments in modernization projects. Now is a good time to get in touch with the state-of-the-art technologies and standard that will guide present and future SAS design.

During this seminar, truly experienced, vendor independent engineers will help you see and understand how to use the core parts of the IEC 61850 standard applied in substation design, monitoring, protection and control applications. You will learn from senior protection engineers, how the protection system will improve and understand the crucial lessons learned since the first projects with IEC 61850 in 2004, all through interactive training, live demos and hands-on exercises.

Monday, 25 April 2016 at 9:00 AM - Friday, 29 April 2016 at 5:00 PM (EDT)

Le Nordelec - 1751 rue Richardson, Suite 4312 Montréal, QC H3K 1G6 CA

Click HERE for more details and registration information.

See you there.

Discrepancy in GPS Timing of 13 Microseconds

Power Delivery systems rely to some degree on Time Synchronization based on global positioning system (GPS).

A time spike in the global positioning system which rippled through the world on January 28, 2016 was caused by a satellite launched in 1990 failing and triggering a software bug!

Although the timing anomaly measured just microseconds, it could have caused significant navigation errors, Richard Easther, head of the University of Auckland's physics department said.
"The rule of thumb is that for every nanosecond of error, you could be out by as much as a foot," Easther said.

"An error of 13 microseconds or 13,000 nanoseconds works out as just under four kilometres."

What would that error mean for Sampled Values? The 13 microseconds are equivalent  to a difference in the angle of 0.234 degrees in a 50 Hz AC system. This seems not to be very critical. But who knows what happens next.

Be aware that our future power system will rely more and more on GPS or other central time sources. So, the power infrastructure does rely on the GPS (or other means) - which by nature does on the power infrastructure. Everything seems to be highly interconnected.

IEC 61850-9-2 Sampled Values In Use

Quite often people ask me about the application of sampled values according to IEC 61850-9-2 (9-2LE). The sampled values require very solid products (publisher, Ethernet Switches, and subscribers). The recent years have shown that the technology has matured to an extend that applications are already available or underway.

Please find useful links:

Click HERE for the paper:

Test and Evaluation of Non Conventional Instrument
Transformers and Sampled Value Process Bus on Powerlink’s
Transmission Network

Click HERE for a related publication:

Australia Leads With Process Bus

Click HERE for the 9-2LE guideline published by the IEC 61850 community.

More and more 9-2LE compliant IEDs are tested and certified.

There are more than 400 IEDs (Server, clients, publisher) that have been certified by the UCAIug:

Source: UCAIug

What’s about subscriber to sampled values?

Click HERE for various protection IEDs implementing the subscriber role for sampled values, e.g., Alstom Distance Protection Relay P446, …

More to come.

IEC 61850-9-3: Precision Time Protocol Profile for Power Utility Automation

IEC TC 57 has published the other day:

IEC/PAS 61850-9-3 (57/1551/PAS):
Communication Networks and Systems for Power Utility Automation –
Part 9-3: Precision Time Protocol Profile for Power Utility Automation

Voting terminates on 2015-05-01

The intent of this publication is to present a widely agreed technical solution for a precision time protocol (PTP) profile of IEC 61588:2009 applicable to power utility automation. There is urgent need in the power industry for a appropriate profile for power automation application to be defined in IEC 61588. This PAS (Public Available Specification) is intended to temporarily be used as a reference.

This allows to meet the highest synchronization classes of 108 IEC 61850-5 and IEC 61869-9.

What does IEC 61850 mean for Power Systems?

A lot. There are many different approaches to describe the benefits. You can start with the System Specification Description (SSD according to part IEC 61850-6, SCL) and go down to the signals and communication. Or you can describe it bottom-up. I like the bottom-up approach:

1. Take a signal (e.g. Voltage phase A in kV) coming trough a serial Modbus (Address 12122) by polling into an IEC 61850 Server device
2. Give it a NAME (MyMMXU1.PhV.phsA) based on a STANDARDIZED Structure (Logical Node MMXU), and
3. Use the protocol (MMS, ISO 9506) to just poll the current value with a MMS Read.

We may have 10 bays with each providing the voltage phase A: then we could model this as follows:
Bay1MMXU1.PhV.phsA
Bay2MMXU1.PhV.phsA
Bay3MMXU1.PhV.phsA
...
Bay10MMXU1.PhV.phsA

That's some basic benefit ... for a first “"brief introduction”.

In addition (there are many other features to look at), e.g.:

1. MMS allows to retrieve the Signal List (device model comprising all logical nodes ...) ...
2. The system configuration language (SCL) allows to carry the "signal list" in form of an XML file ...
3. SCL could carry the complete signal flow between any device in a system: who has which signal to offer, who needs which signal, how are signals carried between the many devices (real-time, non-realtime ...) ...
4. SCL could carry the single line diagram (topology) of an electrical system ...
5. SCL could carry how the information is related to the single line diagram ...
6. …

So, does IEC 61850 add to the complexity of power systems? No that much! See also:

http://blog.iec61850.com/2014/10/does-iec-61850-add-complexity-for.html

Be aware: There is more than IEC 61850 that has to be learned, understood and managed!

Benefits of integrating real-time automation functions into IEC 61850-based SCADA platforms

What are the benefits of using IEC 61850 for real-time automation functions?

The results of an Australian project shows the capabilities of an IEC 61850 based SCADA solution that supports the integration of real-time automation functions into their platform based on the use of IEC 61131 logic programming and IEC 61850 as a means of communication for distributed automation functions.

The performance of simple Centralised Remedial Action Scheme (CRAS) implemented on a SCADA system has been evaluated and compared to the legacy methods to determine if the performance, security, reliability, scalability/flexibility and cost are justified considering the additional complexity of an integrated system. Experimental results show that the system delivers significant benefits including improved system reliability through reduced device count, improved safety with configurable operator interfaces, mobility services and remote diagnostic capabilities, and reduced engineering costs by providing a unified engineering environment that allows simple and seamless configuration based on the use of open standards.

Gaining an understanding of the capabilities of today’s real-time automation products and IEC 61850, along with new distributed automation and control functions will provide decision makers with the confidence to adopt more capable digital platforms and implement a smarter grid.
The additional complexity introduced with those highly integrated systems is justified. However, digital technology products will require organisations to develop specialised skills-sets, work processes and procedures to ensure a successful transition to new solutions and architectures.

Click HERE to download the complete report [580 KB, pdf]

IEC 61850-90-4 Network Engineering – Just Published

IEC just published a crucial document on network engineering:

IEC/TR 61850-90-4 ed1.0
Communication networks and systems for power utility automation -
Part 90-4: Network engineering guidelines

Congratulation to the editors of this great technical report – worth to study in detail!

IEC/TR 61850-90-4:2013 is intended for an audience familiar with network communication and/or IEC 61850-based systems and particularly for substation protection and control equipment vendors, network equipment vendors and system integrators. This Technical Report focuses on engineering a local area network focused on the requirements of IEC 61850-based substation automation. It outlines the advantages and disadvantages of different approaches to network topology, redundancy, clock synchronization, etc. so that the network designer can make educated decisions. In addition, this report outlines possible improvements to both substation automation and networking equipment. This Technical Report addresses the most critical aspects of IEC 61850, such as protection related to tripping over the network. This Technical Report addresses in particular the multicast data transfer of large volumes of sampled values from merging units. It also considers the high precision clock synchronization and "seamless" guaranteed transport of data across the network under failure conditions that is central to the process bus concept.

This 250+ page report could be used as a compendium of solutions for the various applications found in power automation systems. The communication infrastructure is one of the crucial aspects of the future energy delivery system – in the electric power world, gas delivery, heating and cooling systems as well as in E-Mobility. The recommendations given in this new part of IEC 61850 could be applied in many application domains even outside the energy world.

As you may have seen, network infrastructure vendors like MOXA and Kyland have integrated IEC 61850/MMS in their infrastructure.

Click HERE to download the preview of IEC/TR 61850-90-4 ed1.0
Click HERE if you want to buy the report.

IEC 61850: Phoenix Contact offers special Ethernet Ring Solution

Phoenix Contact (Germany) published a paper “IEC 61850 verknüpft Energie- und Automatisierungsnetz” (IEC 61850 connects Energy Networks and Automation Networks) in the latest issue of the Magazine Computer & Automation (July 2013).

IEC 61850 is understood as a huge benefit in the energy delivers system because it is accepted globally.

Phoenix Contact offers special Managed industrial Ethernet switches that combine extensive network performance and security features with complete IEEE redundancy (STP/RSTP/MST) and 15 ms recovery time extended ring redundancy.

The extended ring redundancy is offered as a cost-effective redundancy solution – compared to solutions based on PRP and HSR.

Click HERE for further information on the IEC 61850-3 compliant Ethernet Switches.

IEC 61850/61400-25 for QNX available

Please note that the SystemCorp IEC 61850/61400-25 Stack/API has been ported to QNX 6.5 and PREEMPT_RT Linux. You are invited to visit the SystemCorp booth to discuss further details.

Invitation to Hanover Fair 2013 from 8th to 12th April | E-Energy, Smart Grids

Dear All,
We invite you to visit the booth of SystemCorp (Hall 13, booth C45/1).

SystemCORP offers their IEC 61850 (IEC 61400-25) Stack/API for Substations, Decentraliced Energy Resources , Distribution Automation, Hydro Power Plants, and Wind Turbines, to name few.

The communication stack with integrated APIs has been developed by SystemCorp and most efficiently ported to QNX 6.5 and PREEMPT_RT Linux. Both APIs are also supported by the advanced SoftPLC DACHSview++ with realtime targets under QNX 6.x or PREEMPT_RT Linux..

At the booth you will see an overview about the possibilities, how to apply Embedded Controllers to realize most powerful and cost efficient implementations of standards for Protection Relays, Automation Devices, SCADA, Gateways and Systems.

Best Regards,
Your Team from SystemCorp and STEINHOFF Automation

Mr Karlheinz Schwarz, NettedAutomation will be available at the booth to answer your questions related to the standards.

http://systemcorp.com.au
http://www.steinhoff-automation.com

See you there.

Two new Papers on IEC 61850 Sampled Value Exchange Models

Several well known experts from Australia (David M.E. Ingram, Pascal Schaub, Richard R. Taylor, and Duncan Campbell) have spent some time on analyzing the applicability of IEC 61850 Sampled Value exchange methods and IEEE 1588 time synchronization for high voltage substations. Read what they have figured out:

The first paper focuses on “Performance analysis of IEC 61850 sampled value process bus networks”:

Process bus networks are the next stage in the evolution of substation design, bringing digital technology to the high voltage switchyard. Benefits of process buses include facilitating the use of Non-Conventional Instrument Transformers, improved disturbance recording and phasor measurement and the removal of costly, and potentially hazardous, copper cabling from substation switchyards and control rooms. This paper examines the role a process bus plays in an IEC 61850 based Substation Automation System.

More details and download link.

The second paper is on: “Performance analysis of PTP components for IEC 61850 process bus applications”

New substation automation applications, such as sampled value process buses and synchrophasors, require sampling accuracy of 1 µs or better. The Precision Time Protocol (PTP), IEEE Std 1588, achieves this level of performance and integrates well into Ethernet based substation networks. This paper takes a systematic approach to the performance evaluation of commercially available PTP devices (grandmaster, slave, transparent and boundary clocks) from a variety of manufacturers.

More details and download link.

IEC 61850-5 Edition 2 FDIS Published for Ballot

IEC has published the FDIS for ballot until 2012-11-30:

57/1286/FDIS
Part 5 Ed2: Communication requirements for functions and device models

Extensions in Edition 2 of part 5:

• requirements for communication between substation automation systems to utility automation systems;
• including the interfaces for communication between substations (interfaces 2 and 11);
• requirements from communication beyond the boundary of the substation

Note that part 5 does NOT DEFINE FUNCTIONS!! The scope states:

“The description of the functions is not used to standardize the functions, but to identify communication requirements between Intelligent Electronic Devices … Standardizing functions and their implementation is completely outside the scope of this standard.”

There are other parts of IEC 61850 that go beyond the issue of determining the communication requirements: e.g., part IEC 61850-90-7 defines behavior at the electrical coupling point of a PV inverter. Depending on the configuration (input) of the various settings of a specific model the electric output of the inverter has to follow the “FUNCTION” that is described in the Logical Node model!

See example of the frequency-watt mode control function.

29 Different Ethernet Solutions for Real-time Communication! – What about IEC 61850?

The industrial automation market intended in the mid 90s to get a single Ethernet based international standard for the factory floor. Until today the industry is struggling to keep the number of solutions smaller than 30 (!). 29 solutions are listed at the following site (as of September 2008): Real-Time-Ethernet

One of the most prominent experts in real-time communication (Dr. Karl Weber) came recently (after many tests and investigations) to the conclusion that IEC 61850 is a good candidate for hctp: (Hyper Control Transfer Protocol): Read his presentation on IEC 61850 for htcp

A suggestion to use Ethernet as a fieldbus published in 1991 could be found in the paper “Bridging MAP to Ethernet” [PDF, 720 KB]

The wait for MMS on Ethernet is over (as stated at the end of the paper) – Native Ethernet and MMS are well accepted standard (!) solutions in power systems (generations, transmission, distribution, …): IEC 60870-6 TASE.2 (ICCP), IEC 61850, IEC 61400-25, IEC 61869-9, …

IEC 61850 (not only Ethernet) could be used in almost all application domains that need to exchange information in real-time. Will IEC 61850 replace any of the 29 solutions? IEC 61850 will be used at least in applications that have a close relation to electric power – this is a lot! Think about motor control and protection systems or electric cars … electricity is all over – so will IEC 61850 be in a few years.

Report on the big South-Western US Blackout on September 08, 2011

Some 6 months after the big blackout in the Pacific Southwest, leading to cascading outages and leaving approximately 2.7 million customers without power in parts of Arizona, Southern California, and Baja California, and Mexico, a comprehensive report has been published.

The Key Findings, Causes, and Recommendations are as follows:

“The September 8, 2011, event showed that the system was not being operated in a secure N-1 state. This failure stemmed primarily from weaknesses in two broad areas—operations planning and real-time situational awareness—which, if done properly, would have allowed system operators to proactively operate the system in a secure N-1 state during normal system conditions and to restore the system to a secure N-1 state as soon as possible, but no longer than 30 minutes. Without adequate planning and situational awareness, entities responsible for operating and overseeing the transmission system could not ensure reliable operations within System Operating Limits (SOLs) or prevent cascading outages in the event of a single contingency. As demonstrated in Appendix C, inadequate situational awareness and planning were also identified as causes of the 2003 blackout that affected an estimated 50 million people in the United States and Canada.”

One of the crucial needs for real-time operations is the availability of real-time INFORMATION – to become aware of the situation at the level of the electrical process, primary equipment, secondary functions, and distributed power resources! This requires real-time information exchange which seems to have not been properly installed, available or used. One challenge is to handle the many vendor and user specific communication protocols. It is very surprising that even at the power transmission level the awareness seems to be showing gaps. The situational awareness (supported by real-time information exchange) at the high voltage levels is one of the most crucial issues in power systems!

So, what is the situation in the implementation of real-time information exchange systems in the lower voltage levels? Hm … IEC 61850 installed all over would definitely help to get a good awareness of the situation of the system – allowing to proactively operate the system.

More standard based communication (IEC 61850, DNP3, …) to come.

Read complete power outage report.

Ethernet for Real-Time Applications – IEEE Symposium in Munich

On January 17, 2012 TUEV SUED (Munich, Germany) held a symposium on real-time Ethernet. Ethernet is not fit for real-time – that is what has been said from the very beginning. But: time and technology has changed. “Deterministic Ethernet & Unified Networking - Never bet against Ethernet …”, this is the opening statement of one of the 11 presentations of the symposium. Ethernet seems to be THE backbone of all automation systems in the near future.

The 11 presentations can be downloaded:

1. Opening by TÜV SÜD
2. IEEE 802.1 AVB standards status (audio video bridging, Broadcom)
3. Real-time networks and preemption (Cisco)
4. Latency Scenarios of Bridged Networks (Deggendorf University)
5. Real-time Ethernet Requirements for Automation Applications (iniT)
6. Ultra Low Latency Traffic Class @ Industry (Siemens)
7. Adaptive Scheduling of Streams in RT (Czech TU Prague)
8. AVB and Fault Tolerant Networking (Belden/Hirschmann) – Ethernet everywhere!
9. Robustness Requirement in Industry and Energy (ZHAW, CH)
10. Deterministic Ethernet & Unified Networking (TTTech)
11. IEEE 1588v2 Time Synchronization in Energy Automation Applications – Case Studies from China (RuggedCom) – Huge substation with more than 160 Ethernet Switches!

When I was about to do my diploma thesis at Siemens in Karlsruhe in 1981, my topic was to do some practical analysis of Ethernet. Due to the high cost of two (2) Ethernet MAUs (40.000 DM / 20.000 Euro) it was decided not to purchase the hardware – people did not believe that Ethernet would be an option at all … and forever. Many experts believed in Token Passing.

I did not agree (I was still a student). So, I decided to look for an answer of making shared Ethernet deterministic … it ended up in a patent Siemens got.

More to come … in China and all over. Ethernet and IEC 61850 (based on Ethernet) are providing real standard solutions.