About the IEC protocol


Thread Starter

suresh patel

what is exactly the IEC Protocol for electrical substation controlling and scada application any specification may require for that or it may match with any other protocol like modbus or profibus?

Karlheinz Schwarz

Hello Suresh,

I guess you mean the IEC Project 61850 "Communication networks and systems in substations" based on (UCA™ - Utility Communication Architecture)

IEC 61850 differs from most previous protocols like Profibus FMS or Modbus or DNP in its use of object models of device functions and device components (logical devices composed of logical nodes and data objects). These models define common data formats, identifiers, and controls, e.g., for substation and feeder devices such as measurement unit, switches, voltage regulators, and protection relays. The models specify standardized behavior for the most common device functions, and allow for significant vendor specialization. These models support multivendor interoperability and ease of integration.

The Standard IEC 61850 is developed in international co-operation. The primary target is the electrical substation automation (switchyards and transformers in the medium and high voltage transport and distribution networks).

All major Electrical Utilities (e.g. AEP, EdF, EON, RWE, VEW, ... ) and automation system suppliers (like ABB, Alstom, ... General Electric, SAT, Siemens, ... ) participate in the development of the standard.

The IEC 61850 is, due to its modular structure, its generic basic information for process control, and due to its general functionality, almost predestined for the use in (almost) all areas of industrial automation to achieve unified definition and exchange of any process information.

The gas and water industry in the USA has decided to promote and introduce the IEC 61850. The IEC TC 88 (wind power plants) specifies currently a standard for communication with SCADA systems (IEC 61400-25) based on IEC 61850.

For more details on IEC 61850 check the following web pages:




Best Regards,
Karlheinz Schwarz


Ralph Mackiewicz

There are a number of IEC protocols for substation automation. The latest is:

IEC61850 which is currently at the committee draft stage and progressing. You can obtain a copy of the subset of this document known as Utility Communication Architecture (UCAtm) as IEEE TR1550. There is also technical and product
information on our website. Send me a private email and I can forward you an IEC61850 information sheet that is published by the working groups developing IEC61850.

There is also the IEC60870-5 series of protocols. I might suggest that you contact Triangle Microworks for more information on these

None of these protocols "match" with Modbus or Profibus. Much of IEC61850 is focused on protocol independent abstract object and service models that can be mapped to other protocols. The initial
release of IEC61850 will contain a mapping to Ethernet using MMS based approach of UCA. Other mappings are possible although I do not know of any activity to do this other than with MMS/UCA right now. Modbus is a very primitive protocol
and the mapping of the IEC61850 object and server models to it would seem inappropriate.

Best Regards,

Ralph Mackiewicz
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Alexander Lokotkov

None of these protocols "match" with Modbus or Profibus...

I thought that the IEC 61158-5 (Foundation Fieldbus) Communication Model Type 3 is the same thing as Profibus DP.

Best Regards,

Alexander Lokotkov
Director of Software Engineering
Fastwel, Inc.

Ralph Mackiewicz

> > None of these protocols "match" with Modbus or Profibus...
> I thought that the IEC 61158-5 (Foundation Fieldbus) Communication
> Model Type 3 is the same thing as Profibus DP.

IEC61158 is a fieldbus standard ostensibly for distributed instrumentation. It is not a substation automation standard as the original posting asked about. I'm sure that there might be some applications possible but IEC61158 was not
developed for substation automation like IEC61850 and the IEC60870-5 series.


Ralph Mackiewicz