RMG TME400-VM, Operating Manual

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APPENDIX
Manual TME400-VMF · EN07 · December, 7
th
2020
90
B3 Calculation of the storage size
The total available storage for archives is 506880 bytes.
Archive type Bytes /
entry Amount
entries Sum in
bytes
Parameter archive (custody transfer) 34 300 10200
Parameter archive (non-custody transfer) 34 300 10200
Event archive 12 200 2400
Periodic archive 40 9000 360000
Daily archive 40 100 4000
Monthly archive 40 25 1000
Sum 387800
B4 Archive header
Each archive type contains an administration header that gives information about
how to access the archive.
The header is arranged as follows:
Content Data type Length in Bytes
Position number of the next archive
(largest value = 9999, then again = 0 ) UINT16 2
Index oldest entry UINT16 2
Index newest entry UINT16 2
CRC16 (Modbus) UINT16 2
Total length: 8
There are four headers for each archive type, which are organized in memory as
ring buffers. This is to ensure that the information is stored safely in case of cell
defects in the EEprom. Each time a new archive entry is written, the corresponding
archive header is updated and stored as the next entry in the ring buffer: