Write

This method creates a record in the standard table structure specified by Beckhoff.

Syntax

METHOD Write : BOOL
VAR_INPUT
    hDBID: UDINT;
    sTableName: T_MaxString;
    pValue: POINTER TO BYTE;
    cbValue: UDINT;
    sDBSymbolName: T_MaxString;
    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.
pValue	POINTER TO BYTE	Address of the variable to be logged in the standard table structure.
cbValue	UDINT	Length of the variable to be logged.
sDBSymbolName	T_MaxString	Name that is logged in the table.
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
Write	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.Write method:

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

IF fbPLCDBWrite.Write(
    hDBID:= 1, 
    sTableName:= 'myTable_WithLReal',
    pValue:= ADR(myValue), 
    cbValue:= SIZEOF(myValue), 
    sDBSymbolName:= 'MyValue', 
    eDBWriteMode:= E_WriteMode.eADS_TO_DB_RingBuff_Count, 
    nRingBuffParameter:= 3) 
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
27	Has been dropped
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

With the ring buffer option, only three entries of this name are in the database at any one time. Older entries are deleted.