Additional application data

If you would like to attach additional data from your application to an alarm, you can configure this using the following special AlarmTypes:

Additional fields are defined in these AlarmTypes, which you can fill with values from your application. If an OPC UA client is to be able to use these additional values, it must subscribe to and interpret the corresponding AlarmTypes.

The OPC UA client then receives the additional application data in the fields BkUaEventData and BkUaEventValue of the incoming alarm, for example:

The user-defined EventFields are appended as "UserEventData". This data can be received by OPC UA clients that are logged on to the SimpleEventType "UserEventType".

To use this function, you must define a structure in the PLC that contains both the symbol value to be monitored and the additional values that are to be sent when the alarm is triggered. This structure must be defined as follows:

TYPE ST_CustomStruct :
STRUCT
  value : INT;
  data  : ST_SomeStruct;
END_STRUCT
END_TYPE

TYPE ST_SomeStruct :
STRUCT
  Data1 : INT;
  Data2 : REAL;
  Data3 : LREAL;
END_STRUCT
END_TYPE

The instance of the structure ST_CustomStruct is then enabled as a symbol for Data Access. The structure must also be enabled as a StructuredType.