KROHNE ALTOSONIC V EN - Manual (Page 11)

ALTOSONIC V
Operating Manual rev02 E 7.30850.34.00 Page 11 of 106
3 UFP-V START UP
When the UFP is powered, the UFP-Program starts automatically.
To prevent unattended changes to the initialisation files the data is protected at start-up by:
•
Calculation CRC checksum
• Check data from files on input range limits
• Password
3.1 Calculation CRC checksum
Each file has a CRC checksum. When anything changes in the file, the CRC-checksum will also
change.
At the start-up of the UFP-V the CRC checksums are calculated and checked:
Start-up:
If the checksum of a file is not identical to the one saved at the previous start-up in the CRC_NORM
file, the program switches to fail mode.
CRC checksum:
All data files have a CRC checksum
CRC checksums are saved in file:
CRC_NORM.ufs
CRC_NORM.ufp
CRC_NORM.dat
Back-up of all data files in:
CRC_FILE.ufs
CRC_FILE.ufp
CRC_FILE.dat
CRC checksums and length of each file is saved in:
CRC_BACK.ufs
CRC_BACK.ufp
CRC_BACK.dat
(CRC checksums of these files are within the file)
Fail mode:
Possible cause:
Change of data in file
Only breakable by pin code:
1357