What are Controls?
IEC 61850-7-2 provides specific state machines to allow changing of specific internal and external data attributes by a client. Five control models are provided with the choice of direct or select before operate and normal or enhanced security. Also, a status only model is allowed.
Select before operate requires two commands to be sent – before the operate a select allows to validate the control parameters and reserve the resource.
Enhanced security requires additional information in the request to validate the sender, and provides and additional asynchronous response to verify the operation.