Check if a directory exists and then copy a file in it

Engineering 🇬🇧
alex87
2016-06-16
2016-06-25

  • alex87 - 2016-06-16

    I would like to know a simple method how to check if a directory exists and then copy several files in it.
    More detailed explanation of the problem would be like this: I need to know if user connects a usb key into plc and then copy some files, that PLC made, on to the usb key.

    I was trying to do it with FILE.DirOpen, if it returns error directory doesn't exist and vice versa.
    The code follows and it doesn't work:

    VARS
FileCheckUsb    : File.DirOpen;
FileCheckUsb(xExecute:= TRUE, sDirName:= strUsbKeyDirectory);
IF FileCheckUsb.xDone = TRUE THEN
   xUsbConnected := TRUE;
   FileCheckUsb(xExecute:= FALSE);
ELSIF FileCheckUsb.xError = TRUE THEN
   xUsbConnected := FALSE;
   FileCheckUsb(xExecute:= FALSE);
END_IF

    And here is also code for copying the file from HardDisk to UsbKey. Doesn't work either.

    VARS
FileCopy      : File.Copy;
IF xTransferToUsb THEN
   sFileNameCopy1 := CONCAT(g_sMainDirectory,'FooBar.Recipes.txtrecipe');
   sFileNameCopy2 := CONCAT(strUsbKeyDirectory,'FooBar.Recipes.txtrecipe');
   
   FileCopy(xExecute:= TRUE, sFileNameSource:= sFileNameCopy1, sFileNameDest:= sFileNameCopy2, xOverWrite:= TRUE );
   IF FileCopy.xDone = TRUE THEN
      FileCopy(xExecute:= FALSE);
   ELSIF FileClose.xError = TRUE THEN
      FileCopy(xExecute:= FALSE);
   END_IF
   
   xTransferToUsb := FALSE;
END_IF

    The code is called inside the RECIPE_PRG.

    My PLC is JanzTec em[VIEW] 12 with WindowsCE as an operating system.

    All your help would be much appreciated.

     

  • rickj - 2016-06-25

    I think you need to setup a state machine using case statements. File system operations span multiple executions of you task. So when you trigger an operation by toggling an execute bit you have to advance to the next state where you wait for either the Done or the Error bit to be set. I would look something like the following

    VARS
FileCopy   : File.Copy;
Step      : INT;
IF xTransferToUsb THEN
   sFileNameCopy1 := CONCAT(g_sMainDirectory,'FooBar.Recipes.txtrecipe');
   sFileNameCopy2 := CONCAT(strUsbKeyDirectory,'FooBar.Recipes.txtrecipe');
   xTransferToUsb := FALSE;
   Step := 01;
END_IF
   
 CASE Step OF
   00: // Wait for trigger
    
   01: // Initiate file copy 
      FileCopy(
         xExecute:=TRUE, 
         sFileNameSource:=sFileNameCopy1, 
         sFileNameDest:=sFileNameCopy2, 
         xOverWrite:=TRUE
      );
      Step := 02;
      
   02: // Wait for operation to complete
      IF FileCopy.xDone THEN
         Step := 03;
      ELSIF FileClose.xError THEN
         Step := 04;
      END_IF
   
   03: // Operation completed successfully
      // Do something
      Step := 05;
      
   04: // Operation failed
      // Do something else
      Step := 05;
   05: // Reset operation
      FileCopy(xExecute:= FALSE);
      Step := 00;
 END_CASE
 
     

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