Page 121 - Pipeline Pigging Technology
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Pipeline Pigging Technology
items, e.g. observations. The user moves between screens using the function
keys.
(Hi) To incorporate as much flexibility as possible into the design
Several categories of data are implemented in library form, to avoid data
duplication, provide searching facilities and to allow for the possibility of
extending data types. Example: anode type library, inspection equipment
library.
A system-parameter library holds details such as terminal and output
device characteristics, to accommodate future requirements, and parameter
values used by a number of functions (scaling details, etc.).
A parameter-driven library was designed in order to hold observations
made during surveys (e.g. SU: suspensions) and their parameters (e.g. length,
height). In this way, new observations and parameters can easily be added by
the users.
(iv) To provide adequate security restrictions for the system
It is important to protect the data from unauthorized use. Access to the
system is based on each user having a unique user identification and pass-
word. Access to a specific category of functions is restricted by the user's
security classification. On logging onto the system, the user is presented with
a menu of the available categories based on his classification. To provide a
secure system it is important that users remember to log off at the end of each
session and also not to leave a logged-on terminal unattended. To minimize
the possibility of a breach in security, a timeout facility is incorporated into
the system, so that any terminal which has had no activity for a given period
of time is automatically logged off.
System functions
There are five categories of functions available on the system. Each user
has access to one or more of these depending on their security classification.
Interactive editing
The functions available in this category are used to input or amend any item
of information held on the database. The data entered is validated against the
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