1. | Which types of tags carry a battery? (Select two options.)
|
|
2. | Which memory bank includes the EPC number in Generation 2 tags?
|
|
3. | Which tags are the most suitable for use with smart shelves?
|
|
4. | Where would you place a passive UHF tag on a carton box of corn flakes?
|
|
5. | Where would you place a tag when tagging a six-pack of lemonade in glass bottles? You are using a passive UHF tag. The six-pack case is made of cardboard.
|
|
6. | What type of tag is the most suitable to use in a toll-collection system on a highway so that the cars do not have to slow down or stop?
|
|
7. | What type of field does the inductive coupled system use?
|
|
8. | Which type of a passive tag would you use on thin and tall cases of a clear plastic wrap used in the kitchen? Orientation of the cases cannot be ensured. Circular antennas are installed throughout the entire RFID system.
|
|
9. | Which tags use passive backscatter to communicate information? (Select two options.)
|
|
10. | What is Miller subcarrier?
|
|
11. | A generic passive UHF tag was placed on an empty glass bottle. During testing this tag could not be read farther than 30 centimeters (1 foot) away, even if it was directly facing the reader's antenna. What do you think is the problem?
|
|
12. | What is the advantage of Gen 2 tags over Gen 1? (Select two options.)
|
|
13. | What is the most common use of low-frequency (LF) tags?
|
|
14. | What type of tag would you use to track temperature inside a freezer truck and report this information to the shipping company headquarters?
|
|
15. | What types of passwords are available for EPC Class 1 Generation 2 tags? (Select two options.)
|
|
16. | What could be a reason to use a read-only tag?
|
|
17. | You are a U.S. manufacturer and have a contract to ship goods to Europe. Will you be able to use the same tags you are using to comply with the Wal-Mart mandate?
|
|
18. | How would you tag large plastic bags containing washing powder that will be palletized? How would you organize the pallet?
|
|
19. | Which types of tags can use near-field as well as far-field communication?
|
|
20. | What is the Q factor?
|
|
Answers
1. | A, C. Active tags carry a battery to power their microchip and broadcast the signal to the environment. Semi-passive tags have a power source in the form of a battery as well, but only to power its chip circuitry and possible sensors; they cannot actively transmit signals. |
2. | A. The EPC number is located in memory bank 1, which is called EPC memory. |
3. | B. For smart shelf applications, the most used and most suitable tags are the passive high-frequency (HF) tags, because of their short read range, small size, and relatively good performance around RF-difficult materials. |
4. | D. Corn flakes in a thin carton are dry and easy to penetrate for RF waves. Therefore, you can choose to locate your tag anywhere on the box, avoiding the bar codes, logos, and other information specified by the product manufacturer or distributor. |
5. | C. When tagging a six-pack of beverages, you have to realize that the water and glass are RF-unfriendly materials; therefore, you need to avoid placing the tag on them or near them. Although you could place the tag on the case, the tag would be hard to read if its position caused the reader to have to penetrate the liquid in order to get to the tag. The best spot to place the tag on a six-pack is on its handle or inside it to avoid damage. |
6. | B. The most suitable type of tag for use in toll-collection systems is an active microwave tag, which has a long read range (as all active tags do) and high data-transfer rates. Therefore, a car could drive through an RFID-enabled toll booth at a relatively high speed. |
7. | A. Inductive coupling utilizes the magnetic field created by changing current in the reader's antenna. When a tag with an induction coil gets into this magnetic field, the field induces current in the tag's antenna, which powers the tag's chip. |
8. | A. For any thin and tall cases without enough surface area to accommodate dual dipole tags, you should use a single dipole tag, especially when the RFID system uses circular antennas throughout. When using circular antennas, you do not have to worry about the tag's orientation as much as if you had linear antennas installed. |
9. | B, C. Passive and semi-passive UHF tags use passive backscatter to respond to the interrogator's signal. Active tags broadcast the response directly to the reader by using their own transmitter. Passive HF tags use inductive coupling to communicate. |
10. | B. The Miller subcarrier technique is used for backscatter encoding by EPC Class 1 Generation 2 tags. This technique fits the tag responses between the channels used by interrogators for transmission, which makes it less susceptible to interference. |
11. | C. When the tag was placed onto a glass bottle, the glass detuned the tag; therefore, it could not respond as efficiently. If the short read ranges are a problem, you should consider placing the tag on the bottle cap, embedding it into the cap (only if the cap does not contain metal or a metal lining), or integrating it into the bottle's label. The label should have an insulation layer so that the tag does not touch the glass. |
12. | B, D. Generation 2 tags have higher data-transfer rates that reach up to 640 kilobits per second. Due to this feature, Gen 2 readers can read up to 1,500 tags per second, whereas Gen 1 readers read about 10 times fewer tags per second. Gen 2 tags are also more secure, because they use 32-bit Access and 32-bit Kill passwords and are able to generate and respond with random numbers based on a value Q using a Q algorithm. |
13. | A. Low-frequency tags are used frequently for animal and livestock tracking because of their great body penetration ability. |
14. | D. Active tags with sensors and connection to the cellular phone network will be the most suitable for tracking the temperature and reporting the values to the shipping headquarters. If these tags used only GPS, the headquarters would receive only the tag's location; the temperature would have to be recorded and reported when the truck gets into the reach of an appropriate RFID reader. |
15. | B, C. Gen 2 tags carry two passwords: Access and Kill. After the Access password is input, the tag can be locked or unlocked and other operations can performed. |
16. | C. Read-only tags are still being manufactured (for example, some LF tags or microwave tags), and they are used because of their security and their need for only a simple infrastructure. The tag carries its serial number. When this number is read, it has to be matched to a database to relate it to the object. Therefore, if an unauthorized person interrogated the tag, he or she would receive only the serial number; without access to the database, this number would be useless. |
17. | C. Some manufacturers have developed tags that can work on various frequencies within the UHF band. These tags are the best to use on goods for international trade because they can be read by equipment in the United States as well as Europe and Asia. |
18. | B. The best way to tag the bags with washing powder (or dog food, garden soil, and so forth) is to attach the tags to the sides of the bag and when building a pallet, trying to make sure that the tagged side faces the outside of the pallet. If you put the tag on the front or back of the bag, you could not position these sides to face out of the pallet. These tags would then have to be read through several layers of powder, which includes chemicals and moisture and poses a challenge for RF waves. Although Gen 2 tags achieve better performance even with challenging products, you should still follow the general rules to achieve consistent results. |
19. | A. Passive UHF tags can use far-field communication as well as near-field. Near-field UHF tags utilize the UHF frequency for faster data transfer and can be used for item-level tagging and fulfillment of mandates with one type of frequency. However, as opposed to far-field UHF tags, the near-field tags have better performance around liquids and metals. |
20. | A. The Q factor is a measurement of the quality or efficiency of a tuned circuit. The higher the Q factor, the more efficient the energy transfers between the reader and the tag. |