Monday, July 25, 2011

What Do You Need to Know to Retrieve Process Values from an IEC 61850 Compliant Device?

The answer is quite simple: Almost nothing! It depends – of course – on the availability of software for IEC 61850. Let’s assume that we have a device that plays the role of an IEC 61850 server (providing a data model and services to access the values referenced by the model).

What you need is a software that plays the IEC 61850 client role. There are several options:

  • Purchase source code and build your own client and API (Application Program Interface)
  • Purchase source code and build your own client with an API already incorporated
  • Purchase a client DLL with a simple and easy to use API
  • Purchase a ready to go Browser with a graphical interface

If you want to just retrieve some data values from a IEC 61850 compliant device, you JUST need to know the IP address of the device and a free Browser evaluation software. Download the well known OMICRON IEDScout; the IEDScout runs in Demo mode for free (restricted services!):

Click HERE for more information and download link for the IEDScout.

Install the IEDScout, go to Configure (right), select New Server just by entering the below IP address and assign a server name:

SEL-421: 99.14.76.126

Use default values … click on OK … OK … done. Go to Discover … select the server you just configured … and start communication with the corresponding device. Retrieving the information model may take several minutes! The IEDScout retrieves the model … some thousand messages exchanged … you may trace the messages using the Wireshark analyzer. Start the Wireshark first and then start IEDScout and connect to any IED.

Once you have the model retrieved, open the model tree and read a value in the tree or see DataSets and Control Blocks.

How long did it take to access data values from an IEC conformant device? 30 minutes … may be 45. Maybe it took another 30 minutes to make it run on your Windows system ;-)

How many of the following standards have you read to get access to one of the above IEDs? IEC 61850-7-x, IEC 61850-8-1, ISO 9506-1/-2, ISO 8824, ISO 8825, IEEE 802.1Q, IETF RFC 792, … 1.000, 2.000, or 5.000 pages?

To use a (graphical) interface at a client there was NO NEED to read any of the above standards! What you may need is basic information about IEC 61850.

Of course, this IEDScout is not an API to be used by client applications. You cannot store the retrieved data values … ok, the full version allows to store the model as an SCL document … and store subscribed GOOSE messages.

Another easy to use API is the SystemCorp API used to build a very simple client HMI – a .Net/C# application:

http://blog.iec61850.com/2011/02/updated-c-client-application-for-iec.html

The API (in form of a DLL) can be used to build your own client application in Windows (DLL) or in Linux (library).

Even the use of the DLL for the client and the use of the C# build HMI does not require to understand all details of the protocol.

Lesson 1 learned: To use the comprehensive protocols like IEC 61850, IEC 60870-5-105, IEC 60870-6 TASE.2, or DNP3 … a simple and easy to use API is needed!! Reading thousands of pages of standards is NOT what is required!!

Lesson 2 learned: The efforts to use any of the above protocols is more or less the same! Of course there is a configuration language SCL in IEC 61850 that requires a little bit more information/education …

Implementing the protocols requires a lot of time and efforts … there may be some difference depending on the protocol.

Be happy by just applying simple and easy to use APIs for clients and servers. Get your first data values communicated within hours – not months

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