Future Design MCT-MC 4.3, Руководство пользователя

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MCT-MC
4.3
Logging - 99 - FDC MCT-MC
8.8 Add\View Digital Signatures
The Signature screen allows the user to add digital signatures to historical data log files and view any digital
signatures currently associated with the loaded historical log file.
When a historical data file is loaded, the Signature screen will display any signatures currently associated with
the file. To verify a digital signature and insure that the data file has not been altered, touch the signature in
the list box and press the “Verify” button. The MC will compare the signature to the log file to see if any
alterations to the data have been made. The MC will then indicate if the signature is valid or not.
If the signature is valid, the historical data file is intact and has not been altered. If the signature is invalid, the
data has been altered at some time after the signature was assigned to the file. For data integrity, the MC
automatically signs a data file when logging is stopped; however, this only occurs if the “Auto Interval” is
selected on the Log screen. If a different logging interval is used, the MC will not automatically sign the file and
it must be signed by a user.
To add a digital signature to the historical log file, touch the “Entry” field at the bottom of the screen and enter
in the comment line for the signature (up to 16 characters maximum). Press the “Add” button and the signature
will be added to the log file. The signature includes the date and time of the signature, the user name and
comment line. If a user is not logged into the system, the default user name “Device Manager” will be entered
as the user.
NOTE: The Signature screen is not available if security is disabled. The MC security module must be enabled
in order to digitally sign data log files. See Section 7, Security.