Are You Experienced? Exploring User Experience

in Public Libraries

Barcodes and RFID

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?

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:

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.

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).

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

So how do they work?

If you really want to know, study the next slide. But I have warned you…

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

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?

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.

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)

EM (Electromagnetic)

Targets are strips of metal with magnetic particles for degaussing (desensitizing and resensitizing).

Ex. 3M Tattle Tape

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…

RF (Radio Frequency)

Targets (the small tags) are applied to circulating library materials.

Target cleverly hidden behind pocket!

Shhhhh!

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!

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!

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.

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).

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.

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.)

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

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.

What renders an RFID tag unreadable?

Wood? –no

Plastic? –no way

Human flesh? –now that’s just gross

I am invincible!

Metal!

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

Oh oh!

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.

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.

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.

“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….

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.

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

So how does RFID security work?

Tags can contain security bits (turned off and on by RFID circulation reader pads or self-check machines).

…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).

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.

RFID and barcodes…inseparable friends.

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