Pointer ve Reference tipleri farkları nedir?(İleri Programlama)

    gMpAxisBasic_0.Parameters     := ADR(gMpAxisBasicPar_0); //Servo sürmek için gerekli parametre yapısı aktarılır
    gMpAxisBasic_0(); //Blok çağırılır

    gMpAxisBasicPar_0.Acceleration := 1000;
    gMpAxisBasicPar_0.Deceleration := 2000;
    gMpAxisBasicPar_0.Home.HomingVelocity := 10;
    gMpAxisBasicPar_0.Jog.Velocity := 500;

// My PLC_PRG main

VAR
   FB_byRef_0 : FB_byRef; // My fb referencing another fb
   FB_byRef02_0 : FB_byRef02; // Target fb to be changed inside
END_VAR

// Main PLC_PRG

FB_byRef_0.IN_refFB REF= FB_byRef02_0;   // Reference passing to "FB_byRef" fb

FB_byRef_0(); // Call my fb 1

FB_byRef02_0(); // Call my fb 2

// End of My PLC_PRG main

// My Function block to Point Another "FB_byRef02"

FUNCTION_BLOCK FB_byRef

VAR_INPUT
   IN_refFB : REFERENCE TO FB_byRef02; (* Pass FB by reference *)
END_VAR

VAR
  _ptrVarAdr : POINTER TO INT; (* Get the ADR of the input var *)
  _Test : BOOL;
END_VAR

IF NOT (__ISVALIDREF(IN_refFB)) THEN
   RETURN;  // Checking the adress of Input valid
END_IF

(* Get the adr of the input fb*)

_ptrVarAdr := ADR(IN_refFB);

IF  _Test THEN // Im Changing input of the "FB_byRef02", this i want to do
   _Test := FALSE;
   IN_refFB.inChangeVal := TRUE;
END_IF

// End My Function BLock to Point Another "FB_byRef02"

FUNCTION_BLOCK FB_byRef02

VAR_INPUT
  inChangeVal:BOOL;
END_VAR

VAR_OUTPUT
  outValue :REAL;
END_VAR

IF inChangeVal THEN
   inChangeVal := FALSE;
   outValue    := outValue + 1;
END_IF