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When a compatible SD card is present, the system will periodically copy new data from the onboard flash
log to the SD card. The operation happens once an hour as long as the station is recording and the user is
not present (see below).
The result of the automatic log backup is that a file is created on the SD card. That log backup file contains
the station’s log.
The log backup file holds measurement data (no events) in CSV format. This file is
normally identical to a log file downloaded from the station using LinkComm.
To access the log backup file, safely remove the SD card from the system, and insert the card into a
computer. The FAT32 file system used by the SD card is universally accepted by all major operating
systems.
There is a size limit of 1GB for the log backup file. Once the file reach that size, a new file is created. The
old file is kept after being renamed with the current time.
Please note that the system will not read the log backup files in order to make transmissions. The onboard
flash log must continue to function for the station to operate properly.
Redundant Log
In the case of a catastrophic failure, if the station is no longer operable, it may be possible to retrieve the
logged data from the SD card.
Two backup files are created on the card, providing further redundancy. Under ideal circumstances, both
files are exactly the same. However, if one of the files should become corrupt, the other should remain
intact.
If you find more than two backup files on your SD card, it means that there has been a failure to backup up
the log. The failure could be the result of losing power during the automatic log backup, or it could
indicate a problem with the card.
Expanded Log Storage
Without an SD card, the station has the capacity to hold 1 million sensor readings. By inserting an SD card,
that capacity may be increased. The actual capacity is based on the size of the SD card. Here are some
estimates:
1GB card stores ~25 million readings
4GB card stores ~100 million readings
32GB card will hold ~800 million readings.
Please note that these are rough approximations. Each sensor reading is approximately 35 bytes in size.
The size depends on the measurement label, the number of right digits, and units.
If your station logs so much data that the SD card is required, consider replacing SD cards during routine
maintenance lest the cards get full. If the card capacity is large enough, you may use a USB drive to copy
the log files from the SD card to the USB drive as per
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