Datasets file system overview

All datasets are in emoncms format and consist of a bunch of feeds

Each feed consists of 2 files :

• a .meta file
• a .dat file

All data stored in .dat file are 4 bytes (32 bits) float

To control metas if doubt, open the .meta file it contains 16 bytes

• 4 bytes Unused – deprecated
• 4 bytes Unused – deprecated
• 4 bytes Interval – unsigned integer
• 4 bytes start time – unsigned integer

You may need an editor to perform such a manual check. On a linux OS, Hexditor is a cool choice :-)

Exemple of a meta file opening

On this exemple, the timeserie starts at 1526978160, unix time stamp, which is Tuesday, 22-May-2018 08:36:00 UTC, with a recordng interval of 120 s

Please note endianness is Little Endian (LE)

operation

Most sets can be restored on an EmonPI. The EmonPI is a very cheap and efficient data monitoring and managing platform. Buy it here

When restoring sets coming from deprecated versions of emoncms, a database update can be necessary

Once connected through SSH :

cd /opt/openenergymonitor/EmonScripts/common
php emoncmsdbupdate.php