A common question heard here, followed by "RFID is so
expensive". As with most questions there are two answers for both of
these statements. The use of bar code is something we have become very
familiar with, and it is difficult to find an application that has not
benefited from the use of bar code. However, bar codes do have some very
important limitations that RFID can overcome. Using the two hand in hand
can give some significant benefits to a system. The second question is a
difficult one to answer, but in many questions the answer is "how can
you afford to NOT implement RFID".
Let me explain further. Two areas that bar codes do not
perform well at are: changing data and harsh environments. Let’s face
it, a bar code does not stand up to an automobile paint show very well
(there are of course always exceptions). And once you have printed a bar
code, that’s it. You can always print a new one, but you cannot change
the first one.
RFID tags have the capability to have the data changed on
them many times depending on the specific type. You can store information
and update it as a tag moves through a process, keeping the important
information with the tag (and the item) and so making it available at any
point in its life. Now some items do not need information changed
frequently and this may well be an example of when a bar code will do the
job needed.
Let’s consider an operation where an item is moved
through a series of processes along a "conveyer belt" system. At
each station, the item is taken off the belt and an operation is performed
on the item. It is then returned to the belt to move on to the next
station. The item has a bar code on it, and at each station the bar code
is read as it enters the station and again as it leaves. The work done is
recorded on the central database system. The operator has to move the item
to the reader (or the reader to the item) twice at each station.
Now let’s think about an RFID system in this situation.
The items all have a tag attached instead of a bar code label. The reader
is setup to cover the access to the belt, such that the operator must
remove the item through the readers window when it is removed and
replaced. Because the reader is able to sense the tag in any orientation,
it is not necessary for the operator to swivel the item to get a good
read. As the item is replaced on the belt, the tag is updated with the
latest information about the work in progress.
Think about the time savings alone when the operator does
not have to manipulate the item to a scanner. Think about the benefits of
using a portable reader to interrogate the work in progress at any time.
Now think about the item being used in a harsh
environment. The same tag will work in most situations, hot, cold, dirty
etc. where a standard bar code label might have problems (direct thermal
printed labels don’t like the heat too much) and so give the flexibility
needed to incorporate into a total system.
Where do I use RFID?
