8.5

eventually be closed by a manual or automatic procedure. However, the physical document with the pattern
still exists even if it is closed in regards to the PlanetPress Capture database. Contamination would happen
if a new document is printed with the same pattern, but somehow the "old" document re-surfaces and
someone writes ink on it and docks the pen. When this happens, neither the pen nor PlanetPress Workflow
can understand that the data does not belong on that document and will happily update the "current"
document, possibly closing it. Because the "old" document relates (presumably) to a different client, this
means the "current" document has invalid information.
This can be prevented through simple methods such as printing a date on each sheet and ensuring that
users never sign a document that is older than a certain time, for example 48 hours. These sheets should
simply be destroyed.
Second, contamination can happen in method 1) above if a pen or paper is moved from one location to
another. Similarly to the previous contamination example, if there exists a document in the Capture
Database where the "wrong" data is processed, it will update a document where it does not belong. Again,
neither the pen nor PlanetPress Workflow have any idea that this causes an error until it's too late.
Third, contamination (the most common one) can happen if pattern sequences get mixed up, if pens or
paper gets swapped between users, etc. For example, again using a shipping company (with example 2-A),
if two of the drivers were to meet for a coffee and exchange their pens inadvertently (we hope, anyways), the
pens would be signing the "wrong" documents all day and, when docked, would update the wrong
documents in the database.
In all of these cases, the errors often do not appear when the wrong document is updated - it actually occurs
when the "right" data is processed. This happens precisely because the Pen and Production have no idea
that the wrong data is received and will generally close the document after that "wrong" data has been
processed - this often works with no error. However, when the "right" data is processed, then it tries to
update a document that has already been closed by the "wrong" data, and thus fails.
Safeguards
There are certain safeguards against contamination:
l PlanetPress Capture checks for pattern size and placement. If the data contains ink for a specific
pattern but the ink location does not correspond to the Capture Fields of the document it's updating, it
will fail.
l Errors can be set to stop and revert the whole current batch. If a single error occurs during the pen data
processing, it is possible for this processing to be stopped and all changes the Capture Database