1. What does RFID stand for?
2. How does RFID Work?
3. What does a complete RFID system consist of?
4. Where is RFID currently being used?
5. What is the difference between a reader, a writer (encoder) and a transceiving antenna?
6. What is “tag orientation"?
7. What is “passive RFID"?
8. What is “Active RFID"?
9. What is “Semi-active RFID"?
10. How fast is RFID reading?
11. What RFID frequencies are used in health care applications today?
12. What is a “UID"?
13. How much data can I store on an RFID tag?
14. What is the write range of a tag?
15. I already have a bar code system in place. Can I use RFID at the same time?
16. What are the smallest tags available on the market today?
17. How durable are the tags? That is, what are the lowest and highest temperatures a tag can withstand?
18. Do X-rays affect tags?
19. Do Gamma rays affect tags?
20. Will RFID affect my health?
21. What happens when the printer/encoder encounters a bad tag? How is the operator alerted?
22. Can RFID tags be read through metal?
23. Can RFID tags be read through water?
24. Can RFID tags be stacked?
25. What are possible noise sources?
26. What is the allowable UHF frequency in my country?
27. Is 13.56 MHz RFID secure?
1. What does RFID stand for?
RFID is an acronym for Radio Frequency Identification.
RFID technology provides a wireless, over-the-air interface. Unlike bar code data storage, line-of-sight communication is not necessary. RFID uses an integrated microchip and antenna that reads information. The combination of the chip and antenna is called an RFID transponder, tag or inlet. When the RFID transponder is placed in the field of an RFID reader, information is transmitted to the reader and processed by a computer.
3. What does a complete RFID system consist of?
Included in an RFID system are a number of components including tags, handheld or stationary readers, antennas, and system software. A reader comprises of a transmitter, receiver, control module and communication functions, sometimes called a transceiver in radio terms for it to link to a controlling PC. The transponders or tags are used to identify objects, which can be uniquely programmed with information about the objects. Readers should have an attached antenna, which is used to transmit and receive the radio frequency signal. Each reader is accompanied with PC compatible software that allows the user to read and program tags. Serial communications RS232, RS422/485 or Ethernet are required.
4. Where is RFID currently being used?
Originally adapted during World War II to identify "friendly" aircraft, RFID has proliferated into other applications such as toll payment, supply chain management, cashless payment, ticketing, brand authentication, security access, patron identification and amusement parks.
5. What is the difference between a reader, a writer (encoder) and a transceiving antenna?
Readers, writers are encoders, for RFID purposes, are the same device. Readers are typically built with a memory configuration which contains the firmware (“smarts”) of the reader. When connected to a computer, software can be used to communicated with the reader A transceiving antenna is typically not much more that a copper loop encased in plastic. The copper is “tuned” to the frequency at which it is intended to operate. Electronic leads from the antenna are connected to a reader. Radio signals are then passed from the transceiving antenna to the transponders (tag).
6. What is “tag orientation"?
Tag orientation refers to the geometric position of the transponder (tag) relative to the transceiving antenna. When discussing RFID, three orientations are most frequently mentioned. They are Parallel, Perpendicular, & Horizontal.
7. What is “passive RFID"?
Passive RFID is characterized by transponders that do not have a power source native to them.
8. What is “Active RFID"?
Active RFID is characterized by transponders that utilize an “on board” battery to power the transponding elements.
9. What is “Semi-active RFID"?
Semi-active RFID utilizes characteristics of both passive and active RFID to transmit a signal. When the passive RFID element is “excited” by a nearby reader, it causes the battery on board the tag to generate energy to send a signal back to the transceiving antenna.
10. How fast is RFID reading?
13.56 MHz - Up to about 50 tags per second
915 MHz – Hundreds to thousands of tags per second
11. What RFID frequencies are used in health care applications today?
All of them.
13.56 MHz is typically used for access control, item level tagging, and patient identification.
915 MHz is typically used for asset tracking and locating.
Semi-Active and Active technologies are used for asset, patient and staff locating and capacity management.
UID is an acronym for “Unique Identifier”. When talking about the UID, it is usually in reference to 13.56 MHz RFID under any of the primary standards (14443A, 14443B, and 15693). The UID is encoded into a read only segment of the chip’s memory, and once written can not ever be changed. Under the standards described above, no two UID’s can ever be the same.
13. How much data can I store on an RFID tag?
Passive tags (non-battery) typically have anywhere from 64 bits to 1 kilobyte of non-volatile memory.
Active tags, such as those used in military tags, have memories as high as 128 kilobytes.
14. What is the write range of a tag?
The write range of a tag varies with the type of tag and is typically between 40% and 80% of the read range.
15. I already have a bar code system in place. Can I use RFID at the same time?
Yes. RFID can be used in the same applications as that use any other form of automatic identification and data collection. Software programs must be written to interface with the readers.
16. What are the smallest tags available on the market today?
The smallest smart label form factors are about 1 inch by 1 inch (25 mm square). Specialized RFID tags have been available in sizes as small as 2 mm by 2 mm.
17. How durable are the tags? That is, what are the lowest and highest temperatures a tag can withstand?
The typical operating temperature for an RFID inlay (tag) found in most smart labels is between -25º C and 70º C. Storage temperature typically is between -40 º C and 85º C. These values will vary from manufacturer to manufacturer and will depend on the tag’s components. There are industrial tags available in the market that will withstand temperatures as high as 250º C, which could, for example, stand up to heat sterilization requirements for medical items.
18. Do X-rays affect tags?
For the most part, X-rays will not affect a tag, but this will depend on the intensity of radiation.
19. Do Gamma rays affect tags?
Gamma radiation, typically used in sterilization applications, erases or destroys most silicon-based electronic circuits.
20. Will RFID affect my health?
13.56 MHz is no more hazardous than a car stereo.
915 MHz requires that all antennae are installed in such a way that they are always 9 inches away from where people would be constantly stationed.
21. What happens when the printer/encoder encounters a bad tag? How is the operator alerted?
If a Zebra ®® printer/encoder encounters a bad tag or fails to verify its data, it prints a void error message over the entire face of the smart label. The printer/encoder automatically attempts to program the next tag. Users can select the number of times they want to try to program a good tag. The printer/encoder can then be configured to send an error message to the host.
22. Can RFID tags be read through metal?
No.
23. Can RFID tags be read through water?
13.56 MHz yes, with somewhat reduce read distance.
915 MHz not at all well.
24. Can RFID tags be stacked?
Generall
y, no. The are some specialty tags that do permit a certain level of stacking.
25. What are possible noise sources?
Power supplies e.g. inverters, switched mode power supplies; electric motors, VDU's, other transmitters.
26. What is the allowable UHF frequency in my country?
The frequencies for UHF operation fall into 3 main bands:
| The Americas |
902 MHz to 928 MHz |
| Europe |
865 MHz to 868 MHz |
| Japan |
952 MHz to 954 MHz |
27. Is 13.56 MHz RFID secure?
Data stored on RFID cards is made safe using a number of different security measures:
- One option is to make card cloning more complicated by connecting the card’s serial number to the data stored and additionally encrypting this data with the host-system. This way, the data is not directly readable, even if the key is known.
- Another option is to encrypt the stored data with a customized encryption key, where every card receives an individual code. This method prevents the delivery of the code for all cards for a specific application.
- Monitoring transaction data by using a clearing-system is another method for fraud defense. For this purpose, a transaction counter can be easily installed on the card.
- Another way to increase the level of security is saving the specific time a transaction is made. In case a cloned card enters circulation, the clearing-system should recognize the irregular actions and freeze the card.
- Utilizing RFID technology with a higher grade security architecture is another alternative. Available are Mifare Plus cards, my-d proximity cards and cards with a processor chip.
All of these alternative are available in AARFID™ ware, and they can be easily implemented, even into the infrastructure of already existing systems.
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