USER MANUAL
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Z-GPRS3, Z-UMTS, Z-LOGGER3, Z-LTE-WW
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Using a classic microSD of 4GBytes formatted with a file allocation of 32768 bytes, the number of allocation are
about:
4 000 000 000 / 32768 = about 122070 allocation units
Typically the RTU can save data to a microSD every 15 minutes, in this case the microSD will be full in:
122070 / 96 files for day = about 1272 days = about 3.5 years
Writing to a microSD every 1 minute, in this case the microSD will be full in:
122070 / 3600 files for day = about 34 days
If you need to increase the number of log that can be stored, you must format the microSD with the minimum
allocation unit size.
In a dos shell “cmd” type:
format x: /FS:FAT32 /A:1024 /Q
Where “x” is the microSD drive letter
You will obtain an allocation unit of 1024 bytes so the number of allocation units is:
4 000 000 000 / 1024 = about 3906250 allocation units.
Saving a file every 15 minutes will create a file of about 10K so use 10 allocation unit:
3906250/(10 allocation units*96 file for day) = about 4096 days => about 11 years
And saving every 1 minute:
3906250 / 3600 files for day = about 1085 days => about 3 years
The minimum unit size are typically:
512 Bytes for 2GB microSD
1024 Bytes for 4GB microSD
