6 -- Barcodes and RFID

1. Are You Experienced?
Exploring User Experience
in Public Libraries
Barcodes and RFID

2. Barcodes and RFID?
Why do we need a lecture on them?
Why wouldn’t you want
to know about those
things that are on or in
almost every item in a
library?

3. I think I understand
barcodes…why not
just study RFID?
The majority of libraries still use barcodes,
especially smaller public libraries. Barcodes
are cheap and have worked for decades.
But is it finally time to consider the next
step?
Take a look at barcode technology:

4. Barcode Types
Smart barcodes:
the item info is printed on its own barcode
Smart barcodes are easy to implement
(carry and attach it to the item).
But production costs are high, and human
error can cause major problems.

5. Barcode Types
Dumb barcodes:
the barcode is not pre-linked to a particular item
Dumb barcodes are less expensive than smart
barcodes, less chance of mislinking, better for
certain types of items such as serials and
multivolume sets
But dumb barcodes are more difficult to implement
(the barcode must be attached to an item and then
linked to it, which usually involves transporting the
item to a computer station).

6. How can you obtain barcodes?
Print them yourself: You control the
process (library systems often provide a
barcode printing function as part of the
Acquisitions or Cataloguing module). But
accuracy and reliability (due to the actual
printing process) may suffer.
Have them printed for you: Accuracy and
reliability should be very high

7. So how do they work?
If you really want to know, study the next
slide. But I have warned you…

8. 1. Laser beams emitted from the laser diode hit
the polygon mirror and scan a bar code.
2. The light-receiving element (photodiode)
receives the light of diffuse reflection from the
bar code.
3. The diffuse reflection looks like an analog
waveform as illustrated.
4. The bar code reader converts the waveform
from analog to digital (A/D conversion).
5. The bar code reader identifies the
narrow/wide bars and narrow/wide
spaces using digital signals.
6. The bar code reader converts the
signal combination of the bars
and spaces into data according to
the bar code rules (decoding). It
outputs the decoded data to the
external unit through RS-232C or
an equivalent interface.
http://www.keyence.com.sg/topics/barcode/bar_code/t_guide.php

9. So that’s it?
All the barcode does is make its number
readable by scanner to automate a repetitive
process. Lacking a scanner, simply type in
the number printed on the barcode.
Isn’t that enough?

10. What could go wrong?
A few annoyances:
1. You must have line-of-sight to read a
barcode with a scanner.
2. Constantly looking for a barcode to scan
and manipulating an item is a repetitive
and sometimes difficult process.
3. It is almost impossible to have Automated
Materials Handling (AMH) with barcodes.

11. Do barcodes provide
any security?
No. If you are using barcodes you need an
additional security system. The most popular
security system technologies are:
• EM (Electromagnetic)
• RF (Radio Frequency)
• RFID (Radio Frequency Identification)

12. EM (Electromagnetic)
Targets are strips of metal with magnetic
particles for degaussing (desensitizing and
resensitizing).
Ex. 3M Tattle Tape

13. Targets (the tape) are passed by an
electrical unit with high–powered magnets to
desensitize (release the security signal) or
resensitize (enable the security signal).
Loads of fun…

14. RF (Radio Frequency)
Targets (the small tags) are applied to
circulating library materials.
Target cleverly
hidden behind
pocket!
Shhhhh!

15. To disable the target you cover it using a
card that interrupts the signal so that there is
no alarm when the item goes by the door
gates.
And patrons who
use their pocket
cards as bookmarks
wonder why the
alarm sounds when
they return their
stuff to the library.
Got 'em!

16. And RFID is a security system?
Radio Frequency IDentification
RFID is a way to store data on a tag
(transponder) that can be automatically
received by a reader when the tag comes
within range of the reader.
And it can also act as a security system!

17. What is an RFID tag?
A tag contains a silicon chip and flexible
antenna on a plastic label that can be
attached to an object.

18. What data is on the RFID tag?
In a library capacity, an RFID tag contains
anywhere from 74 to 256 bits of data (can
be more, can be less).
A tag can be write-once or rewriteable.
But most tags include only the barcode
number and no other data (for privacy
reasons…and less data is easier to transmit,
too).

19. What kinds of RFID tags exist?
• Active tags: tags that have their own
battery power supply
• Passive tags: tags that have no power
supply and depend on a reader to activate
them
Note: Libraries use passive tags. If we
wanted to tag and track whales, we would
use active tags. But that is not our job.

20. How does a passive
RFID tag work?
1. The reader emits an electromagnetic signal.
2. When a passive tag comes within range of the reader, this
signal excites the tag, and the tag broadcasts its data.
3. The reader converts the radio waves to digital data and
passes it on to a computer.
4. The computer processes the data and performs some action
(checks the item out, stores the data, sounds an alarm, etc.)

21. Can a reader "read" more than one
tag at a time?
Depending on the anti-collision algorithm,
readers can appear to read several items at
one time. Tags are read in a matter of
milliseconds. Short answer: No

22. What is the range for a reader to
read a tag?
Security gates need to read from
longer distances -- 24 inches.
The typical reader for
circulation purposes reads
from within 8 inches.

23. What renders an RFID tag
unreadable?
Wood? –no
Plastic? –no way
Human flesh? –now that’s just gross
I am invincible!

24. Metal!
Any metal interferes with reception.
(FYI: Damaging the antenna or chip can also render a tag useless.)
Oh oh!

25. What are the advantages of RFID?
• RFID tags do not need line-of-sight to be read.
• Several RFID tags can be read within a very short
period.
• RFID can act as a security system.
• Self-check is simplified for patrons.
• RFID tags can be read/write (i.e., reprogrammable).
• RFID is less physically labor-intensive for staff to
check in/check out.
• RFID can make possible large-scale automatic
handling of library materials.
• RFID allows scanning items on the shelves without
needing the items removed.

26. An RFID reader-wand
can scan the shelves to
find items with the
barcodes we wish to find.
Or even collect barcodes.
Too bad those darn
bookshelves are made
out of metal – but since
they don’t cover the tag,
they just slow us down.
They don’t stop us.

27. What are the disadvantages
of RFID?
• RFID is relatively new for libraries, and
standards are still being developed.
• RFID tags are much more expensive than
barcodes (.25-.50 cents apiece vs. less
than 1 cent!).
• Patrons have (mainly unfounded) privacy
concerns. You know, radio waves and all
that.

28. “True Confessions” time
At my library we were early adopters of
RFID (c. 2004) and we bet on a vendor that
itself bet on a standard for RFID technology.
But library RFID technology was still
evolving….

29. And when our vendor was bought by a
larger vendor in 2009, we had to buy…
All. New. Equipment.
Non-technical explanation: the old stuff did
not work with the new stuff.
Libraries have still not reached complete
interoperability with RFID technology, but
the standards process is now helping.

30. Oh, and besides the new equipment, we had
to re-tag every one of our items! I hope
never to have to do that again…
What did we lose besides money and time?
Well, that about sums it up.
old tag new tag

31. So how does RFID
security work?
Tags can contain security bits (turned off
and on by RFID circulation reader pads or
self-check machines).

32. …and an RFID system that can query an ILS
database if it senses an “on” bit item passing the
security gates can quickly show staff what
sounded the alarm (remember that the RFID tag
has a barcode number in memory).

34. So RFID tags will replace
barcodes, right?
No, not completely.
• RFID tags still fail because they are easy
to damage. Just see how long your tags
last on children’s board books…
• Books with those cool-looking metallic-
base covers also block the signal (so
anything from Danielle Steel and Nora
Roberts!).
• Barcodes are a necessary backup.

35. RFID and barcodes…inseparable friends.

36. But RFID is growing…
so be aware
“Considering RFID? Consider This,” by Stephanie Handy: Computers in
Libraries. Vol. 34 No. 9 November 2014
www.infotoday.com/cilmag/nov14/Handy--Considering-RFID.shtml