Over the past two weeks I’ve been talking to quite a few UK librarians about RFID issues. A few had misconceptions about some aspects of the technology and suggested that it might be helpful if I posted about them here. So here goes…
- RFID self-service doesn’t use sensitisers.
Many libraries invested in Electromagnetic (EM) security systems long before RFID appeared. These usually relied on a thin strip of metal (often called “tattle tape”) hidden in the book’s spine.
When items were borrowed a “de-sensitiser” reversed the polarity of these strips allowing them to pass security gates – set to sound an alarm when they detect sensitised items. High voltages powered the de-sensitiser which transmitted electricity in much the same way as an electric toothbrush does.
When self-service units first appeared in libraries they included these same de-sensitisers together with barcode readers to allow readers to issue their own items.
RFID self-service looks almost exactly like its EM counterpart but works in a completely different way. Instead of changing polarity on a bit of metal RFID depends entirely on data.
Library RFID tags usually comprise an aerial and a tiny chip stuck to a label. The data resides on the chip, while the aerial transmits data values to and from other devices via a scanner/receiver. Security is managed by writing specific values to an area of memory on the chip.
No high voltages. No magnetism. No sensitising or de-sensitising.
Because data is used to carry out the security function it is important for libraries know what data is being written – and how. This is one reason why data standards are so important in RFID installations. RFID scanners using the same frequency – in another library for example – constantly scan for tags, and since not everyone uses the same values to set or clear security data false alarms can and do occur.
- It’s not the RFID system that makes the decisions.
This is a perennial topic. Every year I run a survey of RFID use in libraries around the world and one of the most common complaints I receive is that suppliers of RFID systems are very poor at responding to development requests.
Whilst many of these complaints are fully justified a significant number are asking for changes that could only be made by the management system (aka ILS or ILS) supplier.
All RFID solutions in use in UK libraries depend on a connection to the LMS. It is the LMS that continues to hold all the information – loan policies, borrowing limits, locations etc. All the information required by the RFID system – for displaying items on loan, fines owed or even to determine whether an item may be borrowed – is carried between the LMS system and RFID device by a message of some sort. This may be a web service, an API or some other proprietary means but most often it will be 3M’s “SIP”.
The Standard Interchange Protocol has been developed over many years to allow communication between an LMS and self-service systems (some of them RFID). It was designed primarily to support circulation and has been in use for over almost 30 years.
So RFID suppliers seeking to extend functionality for their clients are often restricted by their dependence on this protocol. Many have sought to improve matters by forming partnerships with specific LMS companies but of course the solutions they develop in this way are by definition bilateral in nature (i.e. they only work for products developed by the two partners).
The UK industry is trying to improve matters by developing an alternative to SIP called the “Library Communication Framework” (LCF).
- Adopting standards doesn’t usually require re-tagging stock
I frequently see messages on the RFID lists (particularly in the USA) from librarians explaining why they have decided not to use standards. One of the reasons given for not doing so is the cost.
There are of course still some costs incurred in switching over to a data standard but one of those often suggested – the cost of tag replacement – is often unnecessary. As I mentioned before a tag comprises a chip, an aerial and a sticky label and it’s the chip that matters here. Most of them are manufactured by the same supplier – NXP – but even if yours aren’t there is every chance that they can be converted without having to replace them.
In the early days of library RFID suppliers used many different manufactures for their tags and some of these products were discontinued, leaving library clients with no alternative but to replace existing tags altogether. That all changed in 2011 and it’s a simple enough matter to ask your supplier whether it’s possible to make the switch. Anyone wanting to future-proof their implementation should seriously consider doing so.
Some companies already offer hardware that will automatically convert tags to the UK standard as they are borrowed and since all UK suppliers have undertaken to support both their own and the UK data standard there should be no need to swap tags.
- You don’t have to buy everything from the same supplier
Before RFID suppliers agreed to support the UK data standard they each decided what data to use and critically where and how to store it on the chip. This often varied from site to site as some librarians mandated data elements they wanted to store.
This state of affairs rapidly created an inflexible market in which libraries had no choice but to buy all their RFID supplies from the same company.
Framework agreements – very popular with the public sector – have tended to perpetuate this practice and most procurements are still based on buying from a single supplier.
Academic libraries have proved more adventurous than their public sector counterparts in asking suppliers to support existing systems – usually by writing bespoke software to read another supplier’s data model – but this has become unwieldy for suppliers and libraries alike so most new installations use the standard – making it easier to mix and match hardware from different suppliers as well as allowing librarians the freedom to buy any new products that support the data standard.