Save and load on a USB PEN every minutes

Hi,
 
           I don't think that save and load in a usb device is very popular here, but this code is very usefull for my project, I use a USB pen as a backup flash drive for my wc32 project. In my case, i need to save var9 or load var9 from a usb flash drive every minute.
 
So,
 
Take a backup every minute or save every minute. 10 secondes is perfect in case of board rebooting.
if var3 == 0, load var9 from the usb pen
if var3 != 0 , save var9 to the usb pen
 
 
 
 
 
PLC code:
 
 
START    
TSTEQ CS 10                      # TEST IF WE ARE AT THE 10TH SECONDE OF THE MINUTE
CALLSUB SAVLOA               # IF YES, CALLSUB THE SAVE AND LOAD SUBROUTINE 
END
 
 
SAVLOA:
TSTEQ VAR3 0                            # TEST IF VAR3 IS SET TO 0 ( THAT MEAN BOARD REBOOT )
LOAD "MyUsb" VAR9             # IF IT'S TRUE, THEN RELOAD THE "MyUsb" VALUE AND PUT IT TO VAR9
TSTNE VAR3 0                            # TEST IF VAR3 AS BEEN CHANGED
SAVE "MyUsb" VAR9              # IF YES, THEN SAVE VAR9 TO "MyUsb" IN THE USB FLASH DRIVE
RET
 
 
Maybe this is not the best way to do that but it works sucessfully for me.
 
 
 
 
 

Maybe add NOP after LOAD and SAVE in PLC, because LOAD and SAVE will skip next line, if read from USB flash drive failed.

Yes! This is important. Now i had nop in plc code and weverything work just fine!