How are IEC 61850 Information Models related to Functions?

The common understanding of information is crucial for the understanding of the related functions that produce, consume, and exchange the information. Information is always "bound" to functions ... no function - no information.

Let's have a look at this function: 

Supervision of a temperature value ... report an alarm to a well known entity when the temperature change rate reaches a value of xyz ... this is the FUNCTION. Now we model it with IEC 61850:

The temperature supervision is modeled in the logical node MySTMP1. We use the data objects Tmp (reported every x minutes), RteAlm (reported when the value of the RteAlmSet is reached, e.g., 0.5 K/s).

This "function" is described in an SCL document ... here the MySTMP1 is bound to a topology (SSD), e.g., room temperature in building so-and-so, the reports are sent to the SCADA system mySCADA-client, ... the factory acceptance test can more or less be automated based on the SCL document.

The IEC 61850 STMP logical node model follows the temperature supervision function!! 

The function was there well before IEC 61850 was born!

IEC 61850 standardizes the information shared with a real function.

The following diagram shows the basic modelling approach in IEC 61850:

• IEC 61850-7-2 defines the foundation
• IEC 61850-7-3 defines the common data classes: MV for measurements, SPS for single point status, and ASG for analogue sessings.
• IEC 61850-7-4 defines the logical node and data object classes.

More details will follow ... stay tuned.

The real challenge with IEC 61850 is: You likely get the feeling when you start reading hundreds of pages: unable to see the wood for the trees.

Let me know if you need help ... after 30 years I can support you.

Is there a problem to connect devices directly to the Internet?

The answer to this question depends ... it is likely that still today responsible people belief that it is no issue ... why?

A well know authority in the field of protecting critical infrastructure reminded people to read the following report (10 years old!):

Project SHINE (SHodan INtelligence Extraction) Findings Report.

I highly recommend you to read the report ... and take it into account in your daily business.

Is IEC 61850 an old Standard?

What do you think? It depends ... IEC 61850 is a standard series of many parts ... published in different years ...

The other day I was reading that somebody on LinkedIn beliefs that IEC 61850 is old ... Oops. Here is what I answered:

I was involved in the development of MMS (ISO 9506, starting mid 1980s), later in ICCP (TASE.2, IEC 60870-6, using MMS), then IEC 61850 (starting 1995, using as well the "old" MMS). 

The AC interconnected power systems have been developed more than 130 years ago ... and improved since then ... AND: Yet we do not complain that they are OLD. They have done a great job. Old wine may be better than young wine ... or?

The standard series IEC 61850 has many aspects to consider: 

• System Configuration Language (SCL, IEC 61850-6) is brand new! 
• GOOSE and sampled values are brand new! 
• The many standard "signals" like MMXU.Hz for frequency measurement are old in the sense that frequency is a physical given.
• There is something we may call "old": the use of the "old" MMS as the protocol for client/server communication according to IEC 61850-8-1 (-8-2). ok.
• There is an alternative new web-based solution under way: IEC 61850-8-3 (a new protocol for client/server in IEC 61850 ... WebSocket transport, ASN.1 message schema, ASN.1 JSON encoding rules, and ASN.1 DER encoding rules).

If you want to learn why the Netherlands DSOs initiated the IEC 61850-8-3, check HERE.

A great reply says: "The transport choice is what stands out: MMS was never reachable from a browser, WebSocket with JSON encoding is, which changes what client tooling can be without an install."

There are other brand new parts of IEC 61850 just published, e.g., IEC 61850-7-410 for hydro, gas, and steam power plants.