Hello community,

I have been tinkering a little bit with a raspberry pi and Sqlite through codesys. I have noticed an instability when it comes to logging at high frequency and calling the function. I am not able to close the Database after writing but that shouldn't be an issue. What I have noticed when I monitor my processes on the pi is an unusual large number of processes that are open from the codesys runtime. After a few cycles, the Visualization hangs and the whole codesys process is killed by the Debian OS, i.e fatal crash of the application. The Sqlite was also successfully written, so the commands were performed as expected.

The code I ran is as follows almost every 1 second:

// Header
METHOD mSqliteWrite : BOOL
VAR_INPUT
    sCmd:               STRING(255);        // an sqlite write command
                                            // 'INSERT INTO fooLog(foo1,foo2)
                                            Values('10','20')' (example not real command)
END_VAR
VAR
        command0 : STRING := 'sqlite3 ';
        command1 : STRING := '/var/opt/codesys/PlcLogic/trend/LogBook.sql ';
        commandout : STRING(1000);

        stdout : STRING(1000) := '';    
        Result : RTS_IEC_RESULT;

        iSize : UDINT ;

END_VAR


// concat the strings to form the right command "sqlite3 path/filename sqlite3 command"
commandout := CONCAT(command0,command1);
commandout := concat(commandout, sCmd);
// // Check size for testing purposes
 iSize := SIZEOF(CommandOut);
// 
// // send the command 
SysProcess.SysProcessExecuteCommand2(pszCommand:=commandout, pszStdOut:=stdout, udiStdOutLen:= SIZEOF(stdout),pResult := ADR(Result));

// // Error handling
// IF Result <> 0 THEN
        // Do something
// ELSE
//  mSqliteWrite := TRUE;
// END_IF

Has anyone come across this problem ? Is there a way around it that doesn't need any kind of third party tools or libs? Is this something relevant to the runtime of the pi or general runtime on other linux based systems ?

Thanks

hey,
you cannot simple reuse a sqlite database which the application uses.
If you want to do your own queries, create your own sqlite database.

Best regards,
Marcel