Operation & Installation Manual V12-V6 2010-05-31.doc
31/05/2010
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Individual parameters are classified according to “roles” in order to define differentiated
access rights. Each “role” is associated with a “typical” user or operator having specific
responsibilities or duties. Users have to be registered with a user name and a password,
when registered the role of the user is also defined, and by consequence also the access
rights of that user.
The following roles have been defined, hereunder listed in according to the rank in the
hierarchy.
Developer:
restricted to KROHNE R&D employees.
Factory :
restricted to KROHNE factory employees, to implement factory settings in the
meter
Service :
restricted to authorized service personnel, to the discretion of KROHNE
Calibrator :
restricted to personnel acting on behalf of a legal calibration station
Supervisor : restricted to personnel acting on behalf of the owner/operator of
the meter (administrator function), to the discretion of the owner/operator of
the meter
Operator:
restricted to personnel acting on behalf of the owner/operator of the meter (for
day to day operation), to the discretion of the owner/operator of the meter
Only a higher rank user is allowed to register a lower rank user. Multiple users having the
same rank or role may be registered.
In addition to restrictions depending of the defined role of a user, a physical “overwrite
disable” contact / jumper protects the configuration parameters. This disables any user from
making modifications to parameters that would influence the measured flow or volume value
(Figure 9-1). This prevents unintentional or unauthorized changes to the parameters and
possibly invalidation of the calibration.
Normally the meter is delivered with a set of parameters suitable for the application.
In case a modification of the configuration file is made, this is stored in its data logging
memory. This information can be retrieved afterwards for auditing and verification purposes.
In case of a modification of the configuration file its “checksum” is also updated.
2.4.2. Start up
As the meter is powered up, the software that is stored in non volatile memory is loaded in
working memory, this initialization process takes approximately 25 seconds.
A “checksum” is appended to the software, each time the software is loaded the checksum is
evaluated to verify the integrity of the software.
Each time the meter is powered up this checksum of the configuration file is also inspected to
verify its integrity.
When the initialization is completed the meter will automatically start its measuring function.
The following list shows the main functions performed by the software and the
microprocessor :
•
the basic transit time measuring process
•
the flow calculations
•
controlling output signals
•
controlling a display
•
communication with other devices
2.4.3. The basic transit time measuring process.
Measuring a single transit time for the signal to travel from one transducer to the other
basically involves the following actions: Generating an electric signal to fire the transmitting
