WriteBySymbol

This method reads the value of a specified ADS symbol and saves it in the standard table structure specified by Beckhoff. ADS symbols from other ADS devices can also be read.

Syntax

METHOD WriteBySymbol : BOOL
VAR_INPUT
    hDBID: UDINT;
    sTableName: T_MaxString;
    stADSDevice: ST_ADSDevice;
    stSymbol: ST_Symbol;
    eDBWriteMode: E_WriteMode := E_WriteMode.eADS_TO_DB_Append;
    nRingBuffParameter: UDINT;
END_VAR

Inputs

Name	Type	Description
hDBID	UDINT	Indicates the ID of the database to be used.
sTableName	T_MaxString	Name of the table that is to be read.
stADSDevice	ST_ADSDevice	ADS device from which a symbol is to be logged in the standard table structure.
stSymbol	ST_Symbol	Symbol name of the variable to be written
eDBWriteMode	E_WriteMode	Indicates the write mode. (append, update, ring buffer)
nRingBuffParameter	UDINT	Additional parameter(s) for the "ring buffer" write mode

Return value

Name	Type	Description
WriteBySymbol	BOOL	Displays the status of the method. Returns TRUE as soon as the method execution is finished, even in the event of an error.

Sample

This sample shows how to use the FB_PLCDBWriteEvt.WriteBySymbol method:

VAR
    fbPLCDBWrite    :  FB_PLCDBWriteEvt(sNetID := '', tTimeout := T#5S);
    myValue         :  LREAL := 43.23;
    myAdsDevice     :  ST_ADSDevice;
    mySymbol        :  ST_Symbol;
    tcMessage       :  I_TcMessage;
END_VAR

// Set ADSDevice Information
myAdsDevice.sDevNetID     := '127.0.0.1.1.1';
myAdsDevice.nDevPort      := 851;
myAdsDevice.eADSRdWrtMode := E_ADSRdWrtMode.bySymbolName; 
myAdsDevice.tTimeout      := T#5S; 

// Set Symbol Information
mySymbol.eDataType        := E_PLCDataType.eType_LREAL;
mySymbol.sDBSymbolName    := 'MySymbol';
mySymbol.sSymbolName      := 'MAIN.myValue';
mySymbol.nBitSize         := 8;

// Call Functionblock
IF fbPLCDBWrite.WriteBySymbol(
    hDBID:= 1, 
    sTableName:= 'myTable_WithLReal', 
    stADSDevice:= myAdsDevice, 
    stSymbol:= mySymbol, 
    eDBWriteMode:= E_WriteMode.eADS_TO_DB_Append, 
    nRingBuffParameter:= 1) 
THEN
    IF fbPLCDBWrite.bError THEN
        tcMessage := fbPLCDBWrite.ipTcResult;
        nState := 255; 
    ELSE
        nState := 0;
    END_IF
END_IF

Result in the database:

ID	Timestamp	Name	Value
28	'2018-01-30 14:04:19'	'MyValue'	41.23
29	'2018-01-30 14:04:29'	'MyValue'	42.23
30	'2018-01-30 14:04:39'	'MyValue'	43.23
31	'2018-01-30 14:06:12’	‘MySymbol’	86.2