FB_NoSQLQueryBuilder_TimeSeriesDB

Function block for defining a query for a TimeSeries database. The query is sent with FB_NoSQLQueryEvt. It is not necessary to call the Build method. Data structures can be described with attributes to affect individual settings.

Inputs

Name	Type	Description
pQueryOptions	POINTER TO BYTE	Specifies the address for the query options.
cbQueryOptions	UDINT	Length of the query options.

Syntax

Definition:

FUNCTION BLOCK FB_NoSQLQueryBuilder_TimeSeriesDB
VAR_INPUT
    pQueryOptions : POINTER TO BYTE;
    cbQueryOptions : UDINT;
END_VAR
VAR_OUTPUT
END_VAR

Methods

Name	Definition location	Description
Build	Local	[optional] This method generates a query for the function block FB_NoSQLQueryEvt from the set parameters.

Example:

VAR
    fbNoSQLQueryBuilder_TimeSeriesDB : FB_NoSQLQueryBuilder_TimeSeriesDB;
    QueryOption_TSDB_Insert : T_QueryOptionTimeSeriesDB_Insert;
    fbNoSqlQueryEvt : FB_NoSQLQueryEvt(sNetID := '', tTimeout := T#15S);
    MyStructArray: ARRAY[1..1000] OF MyStruct;
END_VAR

CASE nState OF 
    1: // init 
        fbNoSQLQueryBuilder_TimeSeriesDB.pQueryOptions := ADR(QueryOption_TSDB_Insert);
        fbNoSQLQueryBuilder_TimeSeriesDB.cbQueryOptions := SIZEOF(QueryOption_TSDB_Insert);

        QueryOption_TSDB_Insert.sTableName := 'MeasurementName';
        QueryOption_TSDB_Insert.sDataType := 'MyStruct';
        QueryOption_TSDB_Insert.pSymbol := ADR(MyStructArray);
        QueryOption_TSDB_Insert.cbSymbol := SIZEOF(MyStructArray);
        QueryOption_TSDB_Insert.nDataCount := 1000; // ArrayLength
        QueryOption_TSDB_Insert.nStartTimestamp := F_GetSystemTime(); // get current twincat time 
        QueryOption_TSDB_Insert.nCycleTime := 1000; // equivalent to 1 ms

    2: // write values 
        IF fbNoSqlQueryEvt.Execute(dbid, fbNoSQLQueryBuilder_TimeSeriesDB) THEN
            IF fbNoSqlQueryEvt.bError THEN
                // do some error handling here
            ELSE
                // success
            END_IF
        END_IF
END_CASE

Requirements

Development environment	Target platform	PLC libraries to include
TwinCAT v3.1 Build 4022.20	PC or CX (x86)	Tc3_Database

Further Information

Build