The term automation function is used to differentiate the functions and communication for controlling (involving automatic functions like tripping a circuit breaker, preventing an operation due to a specific interlock condition, or restoring supply to blacked out customers) and those for monitoring from a supervisory point of view (e.g. a SCADA system keeping track of sequence of events). The use of IEC 61850 models and its relationship with IEC 61499 for control functions is illustrated as below.
From the illustration above shows a single device that performs its function controls unit switchgear (circuit breakers, load break switch, disconnected, etc.). Control functions are represented in the IEC 61 850 as a logical node with the name CSWI. The CSWI have a data object attributes post with ctlVal (control values) that can be handled by the computer terminal. Substation control computer sends a message to the device with CSWI Logical node - it addresses CSWI.ctlVal attribute and set it to Open or Close.
The operation was to close the circuit breaker will not be allowed if the condition is configured to block the opening or closing are met. For example, if an adjacent earthen switch is in the closed position, closing the circuit breaker will cause a short circuit and may damage the main equipment.