Tuesday, February 27, 2024

What is an IED (Intelligent Electronic Device)?

IEC 61850 deals a lot with IEDs. But: What is an IED?

First you can check with two documents of the series IEC 61850:

IEC 61850-1 - Intelligent Electronic Device (IED)
any device incorporating one or more processors with the capability of receiving or sending data/control from or to an external source (for example, electronic multifunktional meters, digital relays, controllers)

IEC 61850-1 - Physical Device (PD)
equivalent to an IED as used in the context of this standard

IEC 61850-5 - Intelligent electronic device (IED)
device incorporating one or more processors with the capability to execute application 
functions, store data locally in a memory and exchange data with other IEDs (sources or sinks) over a digital link

Many years after these definitions have been published, we have different views on the term IED:
Physical IED (in the context of IEC 61850 and IEC 61400-25) - any physical device incorporating one or more processors with the capability of exchanging information (derived from IEC 61850 information models and exchanged with IEC 61850 services for client/server and publisher/subscriber) with other physical device(s). The semantic, the coding and decoding of the exchanged information (messages) follows the standard series.
IED Configuration (in the context of IEC 61850 and IEC 61400-25) - formal description (section in the SCL according to part 6) of the IEC 61850 information models linked to the IEC 61850 information exchange roles client, server, publisher, or subscriber, and the signal flow between physical IEDs.
IED Role (in the context of IEC 61850 and IEC 61400-25) - implementation of the IED Configuration: implementation of the IEC 61850 information model plus implementation of any combination of the following information exchange roles: client, server, publisher, or subscriber.
A Physical IED can host any combination of IED Roles.
Note: A gateway may host a server role to an up-link (first SCL file plus a client role and a subscriber role (both configured in a second SCL file) to the underlying Physical IEDs.
Please note that in SCL a Server configuration comprises the models including the DataSets, Report Control Blocks, GOOSE Control Blocks, SV Control Blocks, and Log Control Blocks:

From a communication point of view GOOSE and SV publisher and subscriber are NOT part of the client/server communication ... 
I hope this definition will help to reduce the disconnects in the communication of the experts.
Let me know what you think.

Monday, February 26, 2024

Mapping of IEC 61850 Models and Information Exchange Services to JSON, HTTP, and MQTT

After I published two sketch videos on IEC 61850 information exchange services and the mapping to MMS, I discuss simple interface options for the last meters between a device that implements the role of IEC 61850 server, GOOSE publisher, and GOOSE subscriber, and the underlying huge world of a myriad of other controllers.

The standard series IEC 61850 and IEC 61400-25 (Wind Power Plants) provide a comprehensive set of standardized information or device models (Logical Nodes, Data Objects, Data Attributes, ...) for a wide range of use cases in the electric power domain (protection, automation, supervision, monitoring, control, ...) and for general applications beyond the electrical world. By the way, tell me where electricity is not a crucial resource in factories, buildings, petrochemical plants, homes, ... it is all over ... required 24/7. These series also comprise information exchange mechanisms like Reporting, Logging, Control, GOOSE, Sampled Values, ... mapped mainly to MMS in IEC 61850-8-1 ... other mappings like mappings to XML and XMPP in IEC 61850-8-2 or MMS, Web Services, IEC 60870-5-104, DNP3, OPC XML DA, ... in IEC 61400-25-4. The most crucial part of IEC 61850 and IEC 61400-25 is the System Configuration Language (SCL, IEC 61850-6).

Many applications use only a very small set of models (a few measurements, control signals, and status signals), a small set of information exchange services, and a simple subset of SCL. Critic comes from experts of various domains: Why do I need to have a complex and comprehensive IEC 61850 stack to implement a simple subset of these standard series? Is there another solution? The wind power plant people developing and maintaining IEC 61400-25 believing that five (5) mappings would help in this regard - really? So, the discussion is still going on. 

A very simple solution has been implemented in various projects: Notation of a subset of the information models and the payload of the messages in JSON. The exchange services could be mapped to various transport mechanisms like MQTT or HTTP ...

This approach would KEEP the models as they are - NO mapping required, just another notation (JSON instead of MMS named Variables etc.). Even SCL could be used.

Whenever there is a need to communicate from a device that plays the role of an IEC 61850 server, GOOSE publisher, GOOSE subscriber, to an underlying (likely simple) device (for the last meters) the decision usually is to use some other communication stacks from a set of 100+ solutions like CAN, Modbus, many fieldbusses, EEBUS, Sunspec, ... and private digital solutions, or even wires only ...

Any of these need to MAP from one standard to another standard, e.g., map MyIED/myMMXU1.Hz.mag.f (measurement of frequency) to register 2246 in one application and to 9817 in another ... hm, that is feasible BUT means a lot of configuration and documentation ... outside the definitions and tools provided by IEC 61850. 

A more reasonable approach would be to use JSON, e.g., to define a DataSet (semantically equivalent to IEC 61850 and MMS) and the report message payload as shown in the figure below:

Please check a couple of blog posts published a few years ago for more details and discussions:




Unfortunately the Beck IPC com.tom Web PLCs with support of IEC 61850, ... disappeared ...
Please let me know your opinion ...

Friday, February 23, 2024

Second Sketch (Video) on Some Basics: The Mapping of IEC 61850 to MMS

IEC 61850 is well accepted globally in the power utility domain. One key issue has always been discussed and criticized: The mapping of the information models (Logical Devices, Logical Nodes, Data Objects ... ) and information exchange services to MMS (Manufacturing Message Specification defined in the standards ISO 9506-1 and ISO 9506-2, developed in the 1980s).

This video (58 minutes) explains the concepts of the mapping to MMS ... ASN.1, ASN.1 BER ... MMS for GOOSE and Sampled Values !?

Click HERE to access the video.

I will continue to produce more sketches (videos) and make them available through Screencast.

I look forward to your feedback.


Monday, February 12, 2024

Global Push for IEC 61850 - The vPAC Alliance for Virtual Protection Automation and Control

IEC 61850 is one of the crucial core components of the architecture of the Virtual Protection Automation and Control (vPAC) Alliance: "Driving standards-based, open, interoperable, and secure software-defined architecture to host protection, automation, and control solutions for power system substations." 

As of the membership list I accessed today 23 well known companies are involved in the alliance: ABB, Advantec, AEP, Black&Veatch, Crystal, Dell Technologies, ... SCE, ... Intel, ... Omicron, Phoenix Contact, Schneider Electric, Siemens Energy, ... 

This kind of alliances will make a chance in how to protect, automate, control, and supervise power systems ... and other system where power is a crucial factor ... like in factories, buildings, ... airports, ...

"A key plays the "virtual protection relay (VPR) concept [pdf document] – an architecture where software defined and virtualized platforms are deployed to host the critical circuit protection functions for an advanced and agile grid. ... 

Standard models of various protection functions were devised for possible interoperability between protection IEDs from any vendor. Standards were prepared for data exchange between devices (station bus) and current/voltage information from field (process bus). Acceptance of the IEC 61850 standards worldwide have resulted in station level and process level communication networks for exchange of digitized raw values (using Sampled Values, or SV, protocol) and processed values/information across the substation devices and beyond the substation to centralized monitoring systems. ..."

It is interesting that it took some 40 years from the definition of Virtual Manufacturing Devices (VMD) in ISO 9506 (MMS, Manufacturing Message Specification) until such a big alliance has the term "virtual" in its name! I have demonstrated on and on since the 80s that this is the future ... 

MMS defines Virtual Manufacturing Devices in clause 6 of part ISO 9506-1 as follows:

I have found in the automation domain that only a few engineers understand abstraction and virtualization. The following wise saying may help ... try it:

If it's there and you can see it It's REAL
If it's there and you can't see it It's TRANSPARENT
If it's not there and you can see it It's VIRTUAL
If it's not there and you can't see it It's GONE
Roy Wills

IEC 61850, IEC 61400-25 (Windpower), and IEC 60870-6 (TASE.2/ICCP) use MMS and the concepts of abstraction and virtualization ... I had a chance to describe these crucial basic concepts as editor of the first edition of IEC 61850-7-1 (Basic communication structure – Principles and models) ... here is what I have written ... some 20 years ago ... still in the current edition:

" ... The IEC 61850 series defines the information and information exchange in a way that it is independent of a concrete implementation (i.e., it uses abstract models). The standard also uses the concept of virtualisation. Virtualisation provides a view of those aspects of a real device that are of interest for the information exchange with other devices. Only those details that are required to provide interoperability of devices are defined in the IEC 61850 series. ..." 

I still like it.

It is great to see that this concept (defined in the 80s) is in the core of future protection, automation, and SCADA ... 

Let me know what you thing ... you find me on LinkedIn as well.

Good luck!

Monday, February 5, 2024

A New Sketch (Video) on the Introduction of Some Basics of IEC 61850 has been Published

In order to give support in learning what IEC 61850 is about, I have produced a 32 minute video (182 MB) for free access. 

This video is one of the easiest ways to understand some basics of IEC 61850 ... you will agree once you finished it ...

I have trained some 4,500 attendees all over the world ... this video takes into account my experience in training these people ...

Click HERE to access the video.

I will continue to produce more sketches (videos) and make them available through Screencast.

I look forward to your feedback.


IEC Opens the Glossaries and Other Contents of Published Standards and Specifications

IEC has opened their databases with the myriad of abbreviations and terms used in the published material. If you want to know what an IED is, just search for IED on the landing page ... 

Here are two examples for the search in the Glossaries and in the publications:


Thanks to the IEC Central Office.

Cyber Security: Power Outages Caused by Animals

I just came about the following website that reports many serious "attacks" on the electric power grids:


It seems that animals are more serious "attackers" of the power grid than hackers ...

Fortunately researchers are "looking" beyond animals ... to humans ... 

Click HERE for information about a crucial R&D project at KIT (Karlsruhe Institute of Technology): "Weak point analysis in energy system protocols"

Saturday, February 3, 2024

IEC 62541 (OPC Unified Architecture) - 3 Additional CDVs published for commenting

IEC TC 65E just published 3 additional Committee Drafts for Vote (CDV) for commenting and voting ... also for public comments!

CDVs for circulation on 2024-02-02 also available in Public Commenting application: (https://www.iec.ch/how-get-involved/public-commenting)

Here are the CDV documents published (official voting period closes April 26, 2024):

IEC 62541-3 ED4: OPC Unified Architecture - Part 3: Address Space Model

IEC 62541-5 ED4: OPC Unified Architecture - Part 5: Information Model

IEC 62541-6 ED4: OPC Unified Architecture - Part 6: Mappings

See also the other 21 CDVs out for comments.

Be aware that these documents are the basis to define domain specific information models like in IEC 61850: MMXU.PhV.phsA for voltage of phase A (L1) in a three phase AC power system or MMXU.Hz for representing the frequency ... 

I guess that a lot of the definitions published in the 24 CDVs will not be implemented in all devices and only a subset of the implemented definitions may be used.

After some 40 years involved in the IEC TC 65 (1982 - 2001), TC 57 (2002 - today), IEC TC 88 (2001 - today), and ISO TC 184 SC5 WG2 (MMS, 1984 - 2000) I am increasingly convinced that IEC 61850 has a lot of advantages compared to other standards ...

Monday, January 29, 2024

IEC 62541 (OPC Unified Architecture) - 21 CDVs published for commenting

Dear All,

IEC TC 65E just published 21 Committee Drafts for Vote (CDV) for commenting and voting ... also for public comments!

CDVs for circulation on 2024-01-26 also available in Public Commenting application: (https://www.iec.ch/how-get-involved/public-commenting)

Here are the CDV documents published (official voting period closes April 19, 2024):

62541-1 ED1: OPC Unified Architecture - Part 1: Overview and Concepts

62541-2 ED1: OPC Unified Architecture - Part 2: Security Model

62541-4 ED4: OPC Unified Architecture - Part 4: Services

62541-7 ED4: OPC Unified Architecture - Part 7: Profiles

62541-8 ED4: OPC Unified Architecture - Part 8: Data Access

62541-9 ED4: OPC Unified Architecture - Part 9: Alarms and Conditions

62541-10 ED4: OPC Unified Architecture - Part 10: Programs

62541-11 ED3: OPC Unified Architecture - Part 11: Historical Access

62541-12 ED2: OPC Unified Architecture - Part 12: Discovery and global services

62541-13 ED3: OPC Unified Architecture - Part 13: Aggregates

62541-14 ED2: OPC Unified Architecture - Part 14: PubSub

62541-16 ED1: OPC Unified Architecture - Part 16: State Machines

62541-17 ED1: OPC Unified Architecture - Part 17: Alias Names

62541-18 ED1: OPC Unified Architecture - Part 18: Role-Based Security

62541-19 ED1: OPC Unified Architecture - Part 19: Dictionary Reference

62541-20 ED1: OPC Unified Architecture - Part 20: File Transfer

62541-21 ED1: OPC Unified Architecture - Part 21: Device Onboarding

62541-22 ED1: OPC Unified Architecture - Part 22: Base Network Model

62541-23 ED1: OPC Unified Architecture - Part 23: Common ReferenceTypes

62541-24 ED1: OPC Unified Architecture - Part 24: Scheduler

62541-100 ED2: OPC Unified Architecture - Part 100: Device Interface

It is a huge list of documents ...
I have looked through the docs and did not find any application domain specific semantic models like in IEC 61850 ... 
Hope you find some time to comment on these documents.

Saturday, December 23, 2023

The IEC 61850 Tissue Database reached 1900 Tissues

The IEC 61850 Tissue Database is a very useful tool to help improving the quality of the standard series. The first Tissue (#1) was posted almost 19 years ago. On December 12, 2023 the Tissue #1900 was posted. In average two Tissues per week have been posted. The Tissue process is accepted all over.

The other day I received a question on the definition of power factor (MMXU.PF). The definition is contained in the Logical Node class MMXU of part IEC 61850-7-4:

When I read the definition I was wondering that there was no definition of the sign of the PF. I thought that somebody must have found this long before me ... I checked the Tissue Database to find the corresponding Tissue ... which is #1721 (Power factor related data objects in LN MMXU) dated September 22, 2020.

The following figure depicts the corrected definition.

Recommendation: In case you belief you found an error in the standard series, check first the tissue database and search ... you may find the correct answer ...

Friday, December 8, 2023

Is National, Regional, and International Standardization Work Important?

The editor-in-chief of the well known German monthly technical magazine "atp - Automatisierungs-technische Praxis" publishes the "atp weekly" discussing this and that. This week he discussed if the various user groups and other interest groups in the process industry (NAMUR, IGR, and VCI) are important for the national, regional, and international standardization. The resume is: Yes it is!

The weekly lists several examples. In the third example he reports that the review and comments of the three above mentioned organizations on a single German draft standard has the potential of savings of 80 Million Euro!! 

Click HERE for the weekly archive (in German only) ... accessible for 6 months.

Not to be involved in the standardization is more expensive than spending time and money to participate and discuss what is needed and what should not be specified in a standard. Less is sometime MORE!

Wednesday, November 29, 2023

Default Passwords May Cause Some Issues - Change Them As Soon As Possible

 A friend of mine reported the following in a SCADA and cyber-security related group:

"The recent cyber-attack on that small water facility outside of Pittsburg is getting increased attention (certainly on this list) . The model and manufacturer of the device in question are known.  The manufacturer's web site has some  documentation on the device, but I do not think they provide the  device's default password.

No need to look hard, it is listed in plain site on CISA's bulletin (below)."

Exploitation of Unitronics PLCs used in Water and Wastewater Systems Release Date November 28, 2023 


Tuesday, November 28, 2023

Up-to-Date IEC 61850 Trial Tools Available From InfoTech (Poland)

Have you ever tried to send or receive messages according to IEC 61850 or IEC 61400-25: Operate, Report, Get, ... GOOSE, Sampled Values, ... try the following updated trial tools ... from InfoTech (Poland) 

Use of Sampled Value Publisher (Sender) according to IEC 61850-9-2LE:

Window for various parameter that can be modified and applied:

Wireshark trace of a SV message:

Access several presentations and the link for the trial versions:

Client/Server, GOOSE Sender & Receiver, SV Sender & Receiver

visualization on a flow diagram and on-line monitoring of GOOSE based on SCD file as input

Simulator of a network of server IEDs based on SCL files (ICD/CID/IID/SCD)  +  creator/editor of ICD

Overview of the Library which we license as source code or as derived binary DLLs for PC/MS Windows

This is the link to the trial version of all tools


Monday, November 27, 2023

Bundesnetzagentur fordert Steuerbarkeit von Wärmepumpen und E-Mobilen ab Januar 2024

Die Bundesnetzagentur hat heute mitgeteilt, wie ab dem 1. Januar 2024 steuerbare Verbrauchseinrichtungen (z.B. Wärmepumpen und Ladeeinrichtungen für E-Mobile) sicher und zügig in das Stromnetz integriert werden können.

"Die Bundesnetzagentur bittet die Netzbetreiber, gemeinsam mit anderen relevanten Markteilnehmern Empfehlungen für die Standardisierung und massengeschäftstaugliche Umsetzung der netzorientierten Steuerung auszuarbeiten. Das ist ein Beitrag zur effizienten Umsetzung der notwendigen Prozesse, aber keine Voraussetzung für deren Start."

Click hier, um zur Pressemitteilung der Bundesnetzagentur vom 27.11.2023 zu gelangen.

Die Bitte der Bundesnetzagentur wurde bereits vor etwa 10 Jahren von den Netzbetreibern und Herstellern von Steuerungssystemen im Voraus "gehört". Das Ergebnis der Lösung (FNN-Steuerbox mit IEC 61850 als Anwendungsschnittstelle) ist bereits heute verfügbar (siehe Lösung von Vivavis in Ettlingen).

Friday, November 24, 2023

IEC 61850 (MMS) Messages Traced with Wireshark, Local Host, and Loopback

Have you tried to trace some IEC 61850 (MMS) messages with Wireshark? 

Usually you expect to run Client and Server on different machines to have communication going through an Ethernet Network! Yes! No!

You could easily run the two on one PC and trace the traffic using Wireshark and select the TCP loopback adapter as the interface for Wireshark to look at !!! It is simple.

The address for the server is:

The Client and Server using the IEDScout 5.2 from Omicron:


Some Impressions From The MATPOST Conference 2023 in Lyon (France)

Andrea Bonetti has posted some impression from the "Digital Twin" world demonstrated at the conference.
Click HERE for the brief report.
What is the difference of a digital device and its twin? In the IEC 61850 domain, a IED (Intelligent Electronic Device) hosts a virtual IED (the models, services, bridges to the applications, ... applications). The host may be a protection device or any other computer platform that can run the software. Why do we talk about twins? We could have triplets or even quadruplets of the same virtual device ... when we run the software on three or four or more platforms.
A digital twin is a digital twin of a digital twin ... the crucial term here is: Virtual Device - this is what an IED in IEC 61850 is!
An IED in the IEC 61850 world could be:
  1. A configuration of an IED section in an SCL document
  2. An IED section of an SCL document hosted, e.g., in a relay or any other controller
  3. A physical relay installed in a cabinet
Note that this virtualization was applied in MMS (Manufacturing Message Specification, ISO 9506) and used in IEC 61850-8-1. In MMS the virtual IED was named VMD - Virtual Manufacturing Device ... some 40 years ago ... hahaha ...
The following may help you to understand what virtual means:
If it's there and you can see it      It's REAL
If it's there and you can't see it    It's TRANSPARENT
If it's not there and you can see it      It's VIRTUAL
If it's not there and you can't see it      It's GONE
Roy Wills
Any question?

Thursday, November 16, 2023

International Conference on Substation Equipment in Lyon (F); 22.-24. Nov 2023

Please note that the 7th European Conference on Substation Equipment (Matpost 2023) with the focus on 

Major infrastructure projects for a carbon-free world and their impact on Substation equipment 

will welcome you in Lyon (France) next week: 22.-24. November 2023.

Click HERE for the program.

There is also a paper presentation on IEC 61850 ... check the program.

Tuesday, November 14, 2023

IEC 61850 Conformance Certification of IEC 61850 Core Documents with Ed2.0 About to End

Richard Schimmel (IEC 61850 Certification Manager at DNV ( former KEMA)) just reported a very crucial information at LinkedIn:

"IEC 61850 certification for Edition 2 will be phased out by the UCAiug. From January 2024 UCAiug will only allow new Edition 2 certificates after passing the Edition 2 with Amendment 1 (Ed2.1)!

If you want to certify IEC 61850 Edition 2, we (DNV) need to show the UCAiug that we received the purchase order before 1st January 2024."

Click HERE for the post a LinkedIn.

Be aware that Edition 2.1 refers just to the yellow marked core parts of IEC 61850 (see IEC 61850 Tissue Database):


Note that EACH part has its own Edition numbering ... there is no IEC 61850 Edition x at all!

The Tissue Database provides the tissues posted, discussed, and solved of the previous editions for each part. This gives you the possibility to see which comments let to a new edition. Comments to Edition 2.1 of the core parts will finally lead to Edition 3.0 of these parts ... Edition 2.1 of the core parts will be valid for the next years ... this is my personal expectation.