When I run the following program, I get in ResultAsync the error 2.
That means invalid parameter for this operation.

What can be the cause of this ?

// DECLARATION:
PROGRAM Test

VAR
udStateOpen: UDINT := 16#FFFFFFFF;
TestFB : SysFileAsyncFB;
SFO : tSysFileOpen;
TestString: STRING;
TestAccessMode: UDINT;
Result, ResultAsync, OUT, hJob: UDINT;
END_VAR

// IMPLEMENTATION:
SFO.szFile := TestString;
SFO.am := TestAccessMode;
SFO.pResult := ADR(Result);
SFO.pulOut := ADR(OUT);
hJob := TestFB.SysFileOpenAsync(ADR(SFO), ADR(udStateOpen), ADR(ResultAsync));

Originally created by: Viacheslav Mezentsev

Up.

The same question. Is there a complete example of using asynchronous (non blocking) read? I need to read input event ('/dev/input/event1').

CoDeSys 3.5.10.x.

Originally created by: Viacheslav Mezentsev

Worked example.

PROGRAM PLC_PRG
var constant
   STATE_IDLE:    byte := 0;
   STATE_CONFIG:    byte := 1;
   STATE_OPEN:    byte := 2;
   STATE_FLUSH:    byte := 3;
   STATE_READ:    byte := 4;
   STATE_READWAIT: byte := 5;
   STATE_CATCHEVENT: byte := 6;
   STATE_CLOSE:    byte := 7;
   STATE_CLOSEWAIT: byte := 8;   
end_var
var   
   ready: bool;   
   step: byte := 1;   
   state: udint;
   result: RTS_IEC_RESULT;
   file : SysFileAsync.SysFileAsyncFB;
   jobparams : SysFileAsync.AsyncJob_Param;
   taskName : string := 'EventTask';
   
   open : SysFileAsync.tSysFileOpen;
   write: SysFileAsync.tSysFileWrite;
   read: SysFileAsync.tSysFileRead;
   close : SysFileAsync.tSysFileClose;
   ulOut : SysFileAsync.RTS_IEC_RESULT;
      
   fileName: string := '/dev/input/event1';
   event: array [0 .. 15 ] of byte;   
end_var
case step of
   
   STATE_CONFIG:
   
      jobparams.TaskParam.pszTaskname    := adr( taskName );
      jobparams.TaskParam.ulTaskPriority    := SysFileAsync.TASK_PRIORITIES.TASKPRIO_IDLE;
      jobparams.TaskParam.ulTaskSleepTime := 10;
      jobparams.TaskParam.phTaskHandle    := SysFileAsync.RTS_INVALID_HANDLE;
      jobparams.TaskParam.ulEndTaskAfterJob := 0;
      
      file.AsyncSetJobParams( SysFileAsync.ASYNCJOB_TASK, 1000000, adr( jobparams ) );
      
      step := STATE_OPEN;
      
   STATE_OPEN:
   
      open.szFile := fileName;
      open.am := SysFileAsync.ACCESS_MODE.AM_READ;
      open.pulOut := adr( ulOut );
      
      file.SysFileOpenAsync( adr( open ), adr( state ), adr( result ) );
      step := STATE_READ;
      
   STATE_READ:
   
      if state = SysFileAsync.ASYNCSTATE_READY or state = SysFileAsync.ASYNCSTATE_ERROR or state = SysFileAsync.ASYNCSTATE_TIMEOUT then
         
         (* The file is correctly opened *)
         read.pbyBuffer := adr( event );
         read.ulSize   := sizeof( event );
         read.pResult   := adr( result);
         read.pulOut    := adr( ulOut );
         State := 0;
         
         file.SysFileReadAsync( adr( read ), adr( state ), adr( result ) );
         
         step := STATE_READWAIT;
      end_if
      
   STATE_READWAIT:
      
      ready := state = SysFileAsync.ASYNCSTATE_READY or state = SysFileAsync.ASYNCSTATE_ERROR or State = SysFileAsync.ASYNCSTATE_TIMEOUT;
      step :=   sel( ready, STATE_READWAIT, STATE_CATCHEVENT );
   
   STATE_CATCHEVENT:
   
      step := STATE_READ;
      
   STATE_CLOSE:
   
      close.pulOut := adr(ulOut);
      file.SysFileCloseAsync( adr( close ), adr( state ), adr( result ) );      
      step := STATE_CLOSEWAIT;
      
   STATE_CLOSEWAIT:
   
      ready := state = SysFileAsync.ASYNCSTATE_READY or state = SysFileAsync.ASYNCSTATE_ERROR or State = SysFileAsync.ASYNCSTATE_TIMEOUT;
      
      (* The file is correctly closed *)
      step :=   sel( ready, STATE_CLOSEWAIT, STATE_IDLE );      
      
   STATE_IDLE:   ;
   
end_case

@Edwin Schwellinger: Would this work with a raspberry pi also?

should work, but meanwhile due security reason only readings allowed in /var/opt/codesys/PlcLogic directory
/dev/input/event1 need then to be added in config file

Just realized that it is the /dev/input/js0 file.
Don't think this is a prob either.

Found the ConfigFile.

Where and how to add /dev/input/js0?

raspberry
[SysFile]
FilePath.1=/etc/, 3S.dat
PlcLogicPrefix=1

[SysTarget]
TargetVersionMask=0
TargetVersionCompatibilityMask=0xFFFF0000

[CmpLog]
Logger.0.Name=/tmp/codesyscontrol.log
Logger.0.Filter=0x0000000F
Logger.0.Enable=1
Logger.0.MaxEntries=1000
Logger.0.MaxFileSize=1000000
Logger.0.MaxFiles=1
Logger.0.Backend.0.ClassId=0x00000104 ;writes logger messages in a file
Logger.0.Type=0x314 ;Set the timestamp to RTC

[CmpSettings]
FileReference.0=SysFileMap.cfg, SysFileMap
FileReference.1=/etc/CODESYSControl_User.cfg

[SysExcept]
Linux.DisableFpuOverflowException=1
Linux.DisableFpuUnderflowException=1
Linux.DisableFpuInvalidOperationException=1

[CmpWebServer]
ConnectionType=0

[CmpOpenSSL]
WebServer.Cert=server.cer
WebServer.PrivateKey=server.key
WebServer.CipherList=HIGH

[SysMem]
Linux.Memlock=0

[CmpCodeMeter]
InitLicenseFile.0=3SLicense.wbb

[SysEthernet]
Linux.ProtocolFilter=3

[CmpSchedule]
ProcessorLoad.Enable=1
ProcessorLoad.Maximum=95
ProcessorLoad.Interval=5000
DisableOmittedCycleWatchdog=1

[CmpUserMgr]
AsymmetricAuthKey=6873d655ac1f166f3743feea42d2f3dd1b39ae40

[CmpSecureChannel]
CertificateHash=09fd8d52be4ddd45a709bc9c95e2aa093b3f5695

[SysSocket]
Adapter.0.Name="eth0"
Adapter.0.EnableSetIpMask=1

;raspberry
[ComponentManager]
;Component.1=CmpGateway
;Component.2=CmpGwCommDrvTcp
;Component.3=CmpGwCommDrvShm

[SysCom]
;Linux.Devicefile=/dev/ttyS

[CmpBlkDrvCom]
;Com.0.Name=MyCom
;Com.0.Baudrate=115200
;Com.0.Port=3
;Com.0.EnableAutoAddressing=1

[SysProcess]
Command.0=shutdown

[CmpApp]
Bootproject.RetainMismatch.Init=1
;Application.1=Application
;Application.1=Application
;Application.1=Application
Application.1=Application

[CmpRasPi]
Architecture=armv6l

[CmpRedundancyConnectionIP]

[CmpRedundancy]

[CmpSrv]

[IoDrvEtherCAT]

It works without adding "/dev/input/js0" in config file.
Great!