Support of the Tc3_Eventlogger

The TwinCAT 3 Database Server supports the TwinCAT 3 EventLogger (TwinCAT 3 Version 4022.20). This makes it possible to read out details of function block events via an interface. Further information on the EventLogger can be found in the TwinCAT 3 basic libraries.

All function blocks of the TwinCAT 3 Database Server support the interface of the Tc3 EventLogger. The interface Tc3_Eventlogger.I_TcMessage is used as the return value of the function blocks. In addition to the return value, the eTraceLevel property is available to determine the event weighting.

Support of the Tc3_Eventlogger 1: Properties

Name

Type

Access

Description

eTraceLevel

TcEventSeverity

Get, Set

Specifies the weighting of the events. Only events with a weighting higher than this value are sent to the TwinCAT system.

Sample:

As an example, the following weighting is specified for the function block FB_PLCDBWrite:

fbPLCDBWriteEvt.eTraceLevel := TcEventSeverity.Warning;

All events that represent at least a warning are now sent here. Events of the "Information" weighting are ignored in this case.

The Tc3_Database function blocks themselves have the output ipTcResult of data type Tc3_Eventlogger.I_TcMessage. All functions of this interface that are offered can be used.

In this sample, the function block is called first. 

1:  // Call Functionblock
    IF fbPLCDBWriteEvt.WriteStruct(
        hDBID:= 1, 
        sTableName:= 'myTable_Struct', 
        pRecord:= ADR(myRecord), 
        cbRecord:= SIZEOF(myRecord), 
        pColumnNames:= ADR(ColumnNames) , 
        cbColumnNames:= SIZEOF(ColumnNames))
    THEN
        IF fbPLCDBWriteEvt.bError THEN
            myTcMessage := fbPLCDBWriteEvt.ipTcResult
            nState := 255; 
        ELSE
            nState := 0;
        END_IF
    END_IF

If an error occurs, we now want to request the event text in the runtime environment. The RequestEventText method can be used for this purpose. Use nLangId =1031 to read the error code in German. This is one of the many functions of the Tc3_Eventlogger.I_TcMessage interface.

255://Request EventText
    IF myTcMessage.RequestEventText(1031,
        ADR(MyEventString), 
        SIZEOF(MyEventString))THEN
        nState := 0;
    END_IF
Further Information