7.6

tagged (with a label) as being for use with a specific pattern sequence also. Each morning, as drivers are attributed a route,
they pick up the correct pen and stack of paper that belong to their route before leaving.
It's very important to note here that the Anoto Digital Pen has absolutely no concept of Pattern Sequences. When "attributing"
a sequence to a pen, this is fully on the PlanetPress Production side, in the Capture Database. This means that if a pen is mis-
labeled or someone picks up the wrong pen, this pen has absolutely no way to know that it is writing on the wrong paper. more
about this in the "Contamination" section below.
b) Process-Based Sequences: In this case, while documents are still printed and their route number attributed to their pat-
tern sequence, the pens do not have this distinction. However, the docking station where the pens are placed at the end of the
day are set to send the pen's data to a specific process which will only handle processing for that specific route number. In this
case, one physical computer (and, presumably, printer) is used for each route, and the driver must dock the pen in the proper
docking station which corresponds to his router number, at the end of the day.
As you may have figured out by now, we are still not actually printing more than 10,000 patterns. The only distinction here is
that we are re-using patterns in separate "zones" (or, well, sequences) and as long as pens and pages using capture patterns
are not exchanged between these zones, they act independently with their own 10,000 pattern limitation.
A small note on PlanetPressMobile:The mobile phone application, "PlanetPress Mobile", which uses bluetooth com-
munication to receive pen data and transmit it to PlanetPress Production, can still be used with both pattern sequence meth-
ods, as it is the equivalent of a docking station on the web. PlanetPress Mobile was added to PlanetPress Capture in version
7.4.
CONTAMINATION
The single but critical danger with any implementation that deals with PlanetPress Capture is "Contamination". Basically, con-
tamination happens when an Anoto Digital Pen writes on a "wrong" document or is docked in the wrong location. This can
happen any number of ways and in different situations, and can have devastating effects in some of those cases so please pay
special attention to this section.
First, contamination is not limited to implementations that extend their patterns through methods 1) and 2) above. Any time
that a pen writes on a "wrong" document, it is considered contamination. A simple example in a basic implementation would be
to print a document with a pattern on it, put this paper aside (or lose it on a desk somewhere) and forget about it. Assuming
proper processes were put in place, this document would 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. Con-
tamination 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 Production can under-
stand 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 infor-
mation.
This can be prevented through simple methods such as printing a date on each sheet and ensuring that users never sign a doc-
ument 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 Production 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
Special Workflow Types