B3 Calculation Of The Storage Size; B4 Archive Header - RMG TME400-VM VMF Series Operating Manual

APPENDIX
B3 Calculation of the storage size
The total available storage for archives is 506880 bytes.
Archive type
90
Parameter archive (custody transfer)
Parameter archive (non-custody transfer)
Event archive
Periodic archive
Daily archive
Monthly archive
Sum
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
Position number of the next archive
(largest value = 9999, then again = 0 )
Index oldest entry
Index newest entry
CRC16 (Modbus)
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:
Manual TME400-VMF · EN07 · December, 7
Bytes /
entry
Data type
UINT16
UINT16
UINT16
UINT16
th
2020
Amount Sum in
entries bytes
34 300
34 300
12 200
40 9000 360000
40 100
40 25
387800
Length in Bytes
2
2
2
2
Total length: 8
10200
10200
2400
4000
1000