Sepam IEC61850 - can I control Logic Outputs directly using the default ICD templates for Series 60 and 80? | Schneider Electric Egypt and North East Africa

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Sepam IEC61850 - can I control Logic Outputs directly using the default ICD templates for Series 60 and 80?

This FAQ discusses the topic of controlling the Logic Outputs (e.g., O101) on a Sepam Series 60 or 80 relay using an IEC61850 Master (Client).

In the default ICD templates provided for the Sepam relays with the CET850 (V2.1) and SFT2841 (V14.1) applications, there are no default controls provided that allow an IEC61850 client to directly control a given Logic Output. For example, the user can access the CSWI node which will give some control of the O1 output assuming that the Standard Control Logic is activated with default settings, but there are no Control Objects provided that allow direct control of other MES120 module outputs such as O101 or O102, for example.

For users wishing to add this functionality, there are at least 2 possible approaches:

a) customize your CID file by adding additional CSWI nodes that would allow you to write to variables in your Logic Equations or Logipam. If you then associated these variables to Logic Outputs in the Control Matrix, you would effectively be able to control the outputs using an IEC61850 client. However, this approach requires modification of the ICD/CID templates, which can be error prone and difficult to manage.

b) create a simple set of Logic Equations (or a Ladder Diagram) to link variables to the Modbus Remote Commands (e.g., TC60, TC61, etc...). Then, access these Remote Commands through the built-in Logical Nodes with the prefix S80RC (S80RC_GGIO1 and S80RC_GGIO2 for Series 80). This approach should generally be easier to maintain and implement in most cases, and it is the approach that will be discussed in this FAQ document.

As shown in the screen shot below taken from the Sepam IEC61850 User Manual (Schneider Electric document #SEPED306024EN), there are 2 Logical Nodes included in the default ICD templates that allow the user access to the Remote Controls that were originally implemented for use with Modbus Communication. Each TC can be controlled as either a single-point or double-point control, as per the description in the manual.

Since the Remote Controls are not directly linked to the Sepam Logic Outputs, we need to write Logic Equations or a Ladder Diagram to link the remote commands to the outputs. Here is a summary of the approach that will be discussed in this FAQ document. It is not the only possible method.

1) add a Remote Command (TC) element to your program (or Logic Equations), and use a TOF timer to extend the impulse signal (to ensure it will be processed correctly). Generally an "unassigned" TC will be used.

2) depending on the needs of the application, use Set and Reset elements to allow the user to modify the state of a variable. Two remote commands could be used - one to assert the variable, and one to de-assert it.

3) finally, the variable should be linked to an element in the Control Matrix. The Control Matrix element is then to be linked to the desired Logic Output in SFT2841, which completes the linkage.

Your program could use only one Remote Command per output, and each time the command was triggered, a pulse of fixed duration could be sent to an output. For this example, we will consider the case when two remote commands are provided per each output to be controlled, as described above.

The following screen captures show the essential parts of a sample Logipam program that gives the structure necessary to control a single Logic Output. The next image shows the screen in SFT2841 where the settings file of the relay must be modified during commissioning. There are also sample Logipam and SFT2841 settings files provided for a Sepam M87 relay attached to this FAQ document - these are for reference only.

To summarize, we have seen how a simple ladder diagram can be created to use an unassigned Remote Command on Sepam and link it to a variable that is linked to an output using the SFT2841 Control Matrix. Once the program has been verified, loaded, and enabled using SFT2841, recall that you must make sure the SFT2841 settings in the matrix are as required for the Logipam program. The screenshot below shows how an IEC61850 test client can be used to view the Logical Nodes for the Remote Control and to test the program.