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Marten

SD Card Locked

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Sometimes we have problems with SD cards. 

At the moment we have  a machine which indicates the micro SD card is locked. In the unilogic software external storage -> is SD card locked the bit is 1

After removal and inserting it into a pc, files can be deleted.  So the PC doesn't see the SD lock.  But why does Unitronics say so?

After formatting the sd card the problem is solved.

Now we have had 3 machines in the field having this problem. This is very unwanted, and needs to be resolved. 

What can be the reason for this? 

 

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Hi,
What size are the cards and how full are they when you have the Locked Issue? How many files in the directories you are having issues with?

DanT

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Hi;

 

Some further information :

IF the SD Card has been formatted in FAT Format : 

By design, FAT carries a few limitations:
  1. Maximum file size is limited to 4,294,967,295 bytes.
  2. Maximum files within folder is 65,536 (i.e. a directory must not be larger than 2,097,152 bytes).
  3. A root directory on FAT12 and FAT16 can hold max 512 files/folders (there is no such limitation for FAT32)

DanT

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Thanks for your reply,

The card is formatted as Fat32

Card size is 32GB. 

I have attached a screenshot of the SD cards properties, shown from unitronics. 

There is a file within the folder Unistream_Files  -> File_System.tar.gz which is 507.730kB so this 507730000 Bytes. This exceeds the size listed above.

But this file I think, is created by unilogic? 

 

SD Card.png

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Hi;

The file you are refering to is a system file from the Updates when you updated the UniStream OS - via UniLogic

             File_System.tar.gz    505,730,000 Bytes   507.730 MegaBytes      well with in the 4 GigaBytes Limit 

That particular folder - UniStream Files  - can be deleted once the UniStream has been updated to the New OS.

Is your program writing files to the Micro SD Card?

      How Often?  How large?

     Into specific folders?     Are you exceeding the number of files in the folder?

 

DanT

 

 

 

 

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Quote

Is your program writing files to the Micro SD Card?

Yes if the machine is  running, the pressure is registred, and written to a datatable.

 

Quote

  How Often?  How large?

This varies, min of 2 minutes, max 2hours.  Sample Interval is fixed at 1 second, sampling two reals.

2 x 60 x 60 = 7200 samples/hour which are 14400 samples/test. 

 

 

Quote

Into specific folders?     Are you exceeding the number of files in the folder?

They are stored a t default location /Smples/Pressure/History  Biggest file i found here is a 50kb size.  I've enabled the checkboxes in the SD card management to ensure the maximum number of 32 files are not exceeded. 

Folders located on the SD are: AlarmLog, DT, Media, Samples, SystemLogs, Unistream_Files, UserLogs. 

Quote

Any differences between the reported capacity of the card on locked vs unlocked?

Nope, both exactly  same

 

 

SD.PNG

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