IEC 61400-25-4 Mappings: IEC 610870-5-104 AND/OR IEC 61850-8-1 MMS?

As an engineer I have been involved in many discussions on protocols – for the last 30 years. Sometimes it seems to be better to just ignore the arguments pro and contra a specific solution. The mapping in IEC 61850 uses ISO 9506 (MMS) as the “transport layer” of the messages required for IEC 61850 client-server applications.

In IEC 61400-25-4 (WIND TURBINES – Part 25-4: Communications for monitoring and control of wind power plants – Mapping to communication profile) there are the following five options defined:

• Web-services
• OPC XML DA
• IEC 61850-8-1 (MMS)
• IEC 60870-5-101/104
• DNP3

Depending on the company you will find one or the other solution. Most applications use MMS – not all.

Yesterday I attended a presentation of a big (well known wind turbine manufacturer). The presentation showed the use of IEC 60870-5-104 to communicate information defined in IEC 61400-25-2 (Information Models). The fourth option expressively allows to use 104. So, does this mean the market will split in five parts? Why should this happen?

The following application running on the WEB-PLC of the Beck IPC com.tom shows that it is quite easy to support one or the other solution or BOTH – at the same time.

The com.tom 5.1 provides two servers: IEC 60870-5-104 AND IEC 61850. The decision which signal to communicate by which protocol is engineered by drawing a line (on a standard web browser!) from the source information (coming from the Janitza UMG 604 power quality analyzer) to the corresponding output signal: IEC 60870-5-104 and/or IEC 61850:

The two clients on top (left QTester104, right IEDScout) can tap the same information. It is no question anymore: either ONE or the OTHER. The communication of the signals can be decided by drawing a simple line – without programming a single line in C/C++ or IEC 61131-3. Sure, the applications to be run on the com.tom family of products can also be programmed in IEC 61131-3 (CoDeSys) and C/C++ … which means: it is more work.

The WEB-PLC Object at the bottom right in the above figure can be an IEC 61400-25-2 object like: WGEN1.PhV.cVal.mag. For the platform these are all just names. I will provide more examples soon.

This solution shows that there is no need to fight for one or the other solution: just use whatever fits with your needs. DNP3 will be available soon … Modbus RTU is already used (see above).