Developments in electronic data recording technology are opening
up new possibilities for the collection, storage and retrieval of
process data, making them appropriate for use in a host of new applications.
Martin Binney of ABB, explains the benefits that electronic data
recorders can bring and how they can be used to transform the way
in which process data is collected and utilised
Developments in electronic data recording technology are offering
new opportunities for the way in which data can be used. As well
as recording the details of a production process, electronic data
recorders are opening up a wealth of new possibilities for the way
in which data can be analysed, presented and utilised throughout
the organisation.
One particular development is the addition of Ethernet communications.
Last year, automation industry experts the ARC Advisory Group predicted
that shipments of device-level industrial Ethernet products are
set to grow 84% annually for the next five years despite difficult
conditions in automation markets. Ethernet's worldwide acceptance
in industrial and office environments has created an eagerness to
expand its responsibilities on the plant floor and beyond. Its performance
capabilities make it ideal for tasks such as data monitoring and
program maintenance.
Where data recorders are concerned, Ethernet communications are
helping to transform the way in which data is retrieved and accessed.
Using Ethernet communications, operators can now remotely access
and download information from electronic data recorders, particularly
ideal for large sites using multiple recorders, or for applications
where data may need to be collected from several geographically
remote sites, such as in the water and waste treatment sector.
Electronic data recorders allow precise variations in process
data to be recorded and displayed as required. They also offer a
range of possibilities for presentation, including the ability to
create and print graphs and reports. Many suppliers can now also
offer units which enable data to be downloaded into an Excel spreadsheet,
allowing it to be interrogated in greater detail.
The validity of the recorded data is also greatly improved by
electronic data recording devices. Events can be automatically recorded
together with the actual time they occurred, unlike paper chart
recorders, which rely on additional details being manually added
to the chart by the operator. Most electronic data recorders also
now enable authorised operators to add an 'electronic signature'
to recorded data to help in tracing who was involved in the process
and any changes they may have made that might affect product quality.
Significant benefits
The ability to store and archive large quantities of data is another
significant benefit of electronic data recorders, particularly in
industries where records are required to be retained for several
years. Up to 2.8 million samples of data can be stored within the
8Mb Flash memory built into the ABB videographic recorders, which
can be archived to SmartMedia or Compact Flash memory cards or transferred
to a PC. With just one 128Mb card typically equivalent to kilometres
of paper chart, the need for storage space is also eliminated.
Electronic data recorders can also offer a significantly reduced
cost of ownership. The solid state construction of electronic data
recorders means there are no mechanical components that need to
be checked or maintained. There is also no need to replace additional
equipment such as charts or pens, which can add significantly to
the initial cost of a paper chart throughout its operational life.
In the food and beverage and pharmaceutical sectors, the main
concern in the take up of electronic data recording technologies
to date has been their ability to safeguard the security and integrity
of recorded data.
Security standards
There is the potential with electronic records for tampering by
anyone with the requisite skills. For this reason, in 1997, the
FDA introduced its 21 CFR Part 11 legislation, which sets out standards
relating to data security and integrity that have to be met by electronic
data recorders. At the moment, the provisions of 21 CFR Part 11
apply specifically just to the pharmaceutical industry, although
it is also starting to increasingly be adopted in the food industry
as the need for traceability and validation of production procedures
gain in importance. The aim of 21 CFR Part 11 is to set out criteria
by which electronic records and electronic signatures will be accepted
in the place of paper records as proof of the validity of a manufacturing
process.
In particular, this criterion focuses on three main areas, namely
security, e-signatures and their validity and the management of
the recorded data.
To protect against the risk of tampering, electronic data recording
equipment must be capable of ensuring total security by preventing
unauthorised access and indicating any changes made that could affect
the validity of the production process. ABB InformIT videographic
data recorders achieve this in a number of ways: l All users are
allocated with individual password and access rights, which allow
them to be identified by the system and set restrictions on their
ability to perform configuration changes which could affect the
process. l Any alterations that are made are recorded by an internal
audit trail, which logs the changes made and records who made the
changes and when, as well as the details of all datafiles created
and many other events key to process data security, such as calibration
changes.
As verification that the correct procedures have been followed
during production and to confirm any changes to configuration, 21
CFR Part 11 requires batch records to be electronically signed by
a person with the relevant authority. ABB videographic recorders
have a user-specific password protected menu, from which the operator
can elect to 'sign' for the data recorded by typing in a message.
This 'signature' is then time stamped and logged by the recorder
to provide a traceable trail of all changes made, including when
they were made and who authorised them.
Criteria for the way in which recorded data is managed and preserved
are also set out by 21 CFR Part 11. Essentially, this is geared
towards preserving the same standards of data integrity as during
the recording process and to eliminate the risk of unauthorised
tampering or alteration of recorded data. In the case of ABB videographic
recorders, specialised analysis software is available which enables
all data recorded to be downloaded for easy viewing and analysis
of recorded process data.
The security of data files created by an SM recorder is ensured
by the use of binary encryption, which preserves the integrity of
the recorded data. Information stored on all of the recorders in
ABB InformIT SM range can be securely accessed via an Ethernet network.
An embedded web server provides online access to web pages created
within the recorder containing details of real-time process data,
which is archived in a secure binary encrypted format.