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:

https://blog.nettedautomation.com/2019/07/iec-61850-8-2-versus-iec-61850-8-1.html

https://blog.nettedautomation.com/search?q=mqtt

https://blog.nettedautomation.com/2019/10/iec-61850-for-monitoring-data-private.html

Unfortunately the Beck IPC com.tom Web PLCs with support of IEC 61850, ... disappeared ...

Please let me know your opinion ...

Next week: IXXAT Smart Grid Gateways at IEC 61850 Global 2019 in London, UK

IXXAT (HMS) will be available at the conference to demonstrate you the latest gateway family supporting IEC 61850, IEC 60870-5-104, Profibus, ProfiNet, Ethernet/IP, M-Bus, ...

IEC 61850 Global 2019
London, UK
Oct 14, 2019, 02:00 AM - Oct 19, 2019, 02:00 AM

Drawing together 150+ IEC 61850 specialists and implementation leaders, this end-user-driven programme focuses on achieving multi-vendor, multi-edition interoperability within the substation and across the wider smart grid.

Click HERE for more details on the event.

New IIoT gateways from HMS allow industrial equipment to communicate with smart grids ...

Click HERE for more details to solve smart grid information models and communications.

Note that the gateway will come with MQTT as well ...

Click HERE for the Gateway with MQTT support.

IEC 61850 For Monitoring Data - Private or Standard?

One of the most crucial issues in the management of energy systems is: HOW TO share or exchange useful information generated by a myriad of sensors and applications needed by hundreds of applications?

Lets assume that lakes of information are generated every second. Usually this information is stored in silos of vendors specific solutions and communicated using one or more vendor specific communication solutions ... as shown in the following sketch drawn by our grandson Jan Oliver:



The expectations to apply IEC 61850 are high! BUT quite often vendors argue, that it is easier to use their private solutions - faster and saves time and costs! This may be true for the first phase of a project - but in the long run and in the view of the life time cost it may be completely opposite.

Three experts from Vattenfall DSO (Sweden; Vincent GLINIEWICZ, David EROL Anders JOHNSSON) have reported at the CIRED conference 2019-06 in Madrid (Spain) from an implementation of a pilot project using IEC 61850 and CIM  with the title:

LEVERAGING INDUSTRY STANDARDS TO BUILD AN ARCHITECTURE FOR ASSET MANAGEMENT AND PREDICTIVE MAINTENANCE

Excerpt from the paper:

"... However the data unfortunately currently often remain unused and unshared outside of the substation or specific silos for various reasons, some technical (e.g. cyber security, system incompatibility), some and organizational (e.g. vendor lock-in, siloed applications and organizations).
Additionally, with an increasing number of use cases requiring access to information, there is a growing number of information flows needed not only between data sources and central level applications but also between these central level applications. Without an IT architecture that allows reuse of information flows, there are legitimate concerns that the opportunities that digitalization promises might be delayed and costly or even worse, not be achievable.
As a result, Vattenfall Eldistribution sees a standard based integration approach as a cost-effective approach that seems to offer in the long run low integration costs and more importantly a greater flexibility, going from supplier specific integrations to a more generic approach. ...

We would also like to highlight some of the deviations from the standards that were observed during this pilot:

The pilot made use of a REST API towards the real time data historian (RTDH in fig. 2), although there was no mention of REST in the 61968-100 standard. One could however expect, given the increasing popularity and use of RESTful services in most industries, that the standard will soon follow and that the mention will be added in a further edition on the standard.
The gateway used in the pilot was a prototype base on a technical report (IEC TR 61850-90-2) [Using IEC 61850 for communication between substations and control centres] which is not yet a standard. This might explain why there doesn’t seem yet to be a complete and robust 61850-90-2 compliant product on offer in the market. Another alternative considered for the pilot gateway was the use of IEC 61850/MMS towards the substation and the use of web services (either RESTful+ JSON or SOAP) to communicate northbound instead of the IEC 61850/MMS used in the pilot. SOA has indeed a robust and well developed architecture for distributed computing, and this should be leveraged. There however did not seem to be any products available on the market. This alternative will be explored in a coming pilot. ..."

The paper concludes:

"Although the pilot was made for a primary substation, the widespread use of the IEC 61850 standards series make the results of this pilot not only applicable for primary substations, but potentially also secondary substations and microgrid.
Following the successful pilot, the next step is to look at how to fully implement and verify the concepts in a real substation and to secure production grade components where prototypes have been used as well as test the architecture through other smart grid use cases."

Click HERE for the full paper.

I have run an UCA/IEC 61850 pilot project with Anders Johnsson some 20 years (!) ago:

Two reports out of this pilot project and other discussions have been published in 2002:

Wind Power Communication
Verification report and recommendation

Click HERE for the Report.

Wind Power Communication - Design & Implementation 
of Test Environment for IEC61850/UCA2

Click HERE for the Report.

Enjoy the reports.

By the way: It took some 20 years to understand that the mapping of IEC 61850 models and communication protocols to MMS (ISO 9506) should be extended by a much easier and simpler mapping to JSON and, e.g., MQTT or http ...

It is not too late for such an additional standardized mapping ... e.g., as IEC 61850-8-3.

It may take another 10 years before this becomes true! Hope it will happen a bit earlier!

Further reading on the subject see discussion of IEC 61850-8-1 versus 8-2 (by 2024-02-25: 4074 visits of the post since July 2019).

Other people have similar ideas and published the following paper:

International Electronical Committee (IEC) 61850
Mapping with Constrained Application Protocol
(CoAP) in Smart Grids Based European
Telecommunications Standard Institute
Machine-to-Machine (M2M) Environment

IEC 61850 All Over At CIRED Conference 2019-06 in Madrid Spain

I was really surprised to browse through some of the 51 papers presented at the CIRED Conference 2019-06 in Madrid Spain that refer to IEC 61850 !!

Click HERE for the CIRED search engine. Enter "61850" and you will find the links to the 51 papers presented this year that mention IEC 61850 by some means or other.



Unfortunately I don't have time to study them all in detail ... hope to find some time soon.

While searching the web, I found another very interesting paper:

International Electronical Committee (IEC) 61850
Mapping with Constrained Application Protocol
(CoAP) in Smart Grids Based European
Telecommunications Standard Institute
Machine-to-Machine (M2M) Environment

Click HERE for accessing that paper. More to come ...

Why Is It So Easy To Map IEC 61850 Signals to JSON Objects?

IEC 61850 defines Device Models for the exchange of information between any two or more entities. The Models are structured as unique branches of a tree.That means:

Each path from the Device (Root) to 

any node or leave of the trees is unique

The signals are composed of an access reference (LDName/LNName.DOI. ...) and the value that corresponds with the path.

Example of two leaves:
LDName/Tran1STMP1.Tmp.mag.f = 23.5 (Temperature value)
LDName/Tran1STMP1.Tmp.units.SIUnit = °C (Temperature engineering units)

These are key-value pairs that could easily map to JSON Objects:

"LDName/Tran1STMP1.Tmp.mag.f " : "23.5"
"LDName/Tran1STMP1.Tmp.units.SIUnit" : °C

These JSON objects are

• Light-weight
• Language independent
• Easy to process with Python, ...
• Text based and human readable 
• JSON Schemas could support automatic (syntax and semantic) checks
• JSON is supported by many controllers

The controller of our PV inverter from Fronius has an http/JSON interface. The following request (lines 1-3) returns many common inverter data (line 21ff):



Lesson learned: Controller in inverter could easily provide an http/JSON interface.

The Device Model is a virtual model that could be configured using the SCL (System Configuration Language, IEC 61850-6). The Device Model is implemented in an IED and could be accessed to get the self-description, read, write, send/receive reports, publish/subscribe, ...

An IEC 61850 Server hosted by an IED could easily map the model to JSON objects that may be communicated with MQTT, HTTP, ...

The mapping to JSON is quite easy. It could be implemented by a simple automatic process that parses the model (SCL/XML), searches for the paths and concatenates the names from the root to the leaves to get the reference! AND: the mapping preserves the semantic - the meaning represented by the path name.

The mappings of IEC 61850 Models to IEC 60870-5-104, DNP3 or Modbus would result in messages that have lost the semantic of the signals. These solutions have mainly numbers as reference - these numbers have no meaning in the communication.

Beck IPC offers MQTT@CHIP in addition to IEC 61850 and other protocols

Beck IPC (Wetzlar, Germany, a subsidary of HMS) is known for their solutions on a single CHIP offering support for IEC 60870-5-104, IEC 61850, Modbus, CANBus, Profibus, Profinet, OPC UA, ... now offers MQTT@CHIP as an additional solution.



The MQTT can be configured on the WEB PLC like it is implemented for other protocols:



In the above example I have mapped a signal from an IEC 61850 Server the signal MMXU1.TotW.instMag.f to a MQTT message. This way you can tag the signal as a JSON Object!!

JSON Objekte:
{ „MMXU01.TotW.instMag.f“:  2325, „MMXU01.Hz.instMag.f“:  49.98 }

Message specification:



This way you can send MQTT messages with values from any other protocol or from the IEC 61850 client or server model. This way you can even map to/from GOOSE messages.

I have used the solution running on the IXXAT Smart Grid Gateway. The WEB PLC version 19.2 is required to run MQTT on the gateway.

Very well done!

IEC 61850 Products at CIRED June 3-6, 2019 - Madrid (Spain)

3-6 June 2019, Madrid, Spain

SystemCORP will participate together with Advantech in the CIRED Exhibition in Madrid, Spain. It promotes the SystemCORP ADH Software, a flexible and complete data communication and process automation package, fully integrated in Advantech data gateways.

Based on a distributed real-time database and application management system almost any SCADA communication protocol can now be used as client or server on Advantech modules. SystemCORP offers most commonly used communication protocols such as IEC 61850, IEC 60870-5, DNP3, Modbus and JSON/MQTT as part of a standard communication library for SCADA and Cloud integration. An integrated IEC 61131 compliant programmable logic controller (PLC) extends the capability of the ADH as a true virtual SMART Grid device ready to be installed in distribution automation and smart gird projects.

For application configuration, the eNode Designer, IEC 61850 ICD Designer and IED Configurator tools simplify system engineering and result in reduction of project costs and implementation time. No special tools are required for establishing secure communication with cloud applications.

To know more visit our booth no H1/G2 at the IFEMA North Convention Centre. Address: IFEMA, Av. Partenón, Nº 5, 28042 Madrid, Spain. Entrance is free.

For any more information please check the event website: http://www.cired2019.org/