Glossary Of RfidTerms

Glossary Of Rfid Terms -- C

2020-04-10 10:18:32 M&W SmartCard 51



An electric circuit element used to store a charge temporarily. A capacitor usually consists of two metallic plates separated and insulated from each other by a dielectric substance.

Card operating system

The software program stored in the smart card IC, which manages the basic functions of the card, such as communication with the terminal, security management and data management in the smart card file system.

Carrier frequency

A frequency used to transmit data.

Carrier wave

A radio wave of a specific frequency that is modulated or changed in some way in order to transmit data. The amplitude of the carrier wave can be increased—for example, to indicate a one or zero of binary code.

Central processing unit

The brains of a computer, which controls all the other parts of the computer.


A code added to the contents of a block of data stored on an RFID microchip that can be checked before and after data is transmitted from the tag to the reader to determine whether the data has been corrupted or lost. The cyclic redundancy check is one form of checksum.


A programmable digital electronic component (also called a microprocessor) designed to incorporate the functions of a central processing unit (CPU) onto a single semiconducting integrated circuit (IC). Multiple chips can serve as the CPU in a computer system, embedded system or handheld device.

Chipless RFID tag

An RFID tag that doesn't depend on a silicon microchip. Some chipless tags use plastic or conductive polymers instead of silicon-based microchips. Other chipless tags use materials that reflect back a portion of the radio waves beamed at them. A computer takes a snapshot of the waves beamed back and uses it like a fingerprint to identify the object with the tag. Companies are experimenting with embedding RF reflecting fibers in paper to prevent unauthorized photocopying of certain documents. Chipless tags that use embedded fibers have one drawback for supply chain uses—only one tag can be read at a time.

Circular-polarized antenna

A UHF reader antenna that emits radio waves in a circular pattern. These antennas are used in situations where the orientation of the tag to the reader cannot be controlled. Since the waves are moving in a circular pattern, they have a better chance of hitting the antenna, but circular-polarized antennas have a shorter read range than linear-polarized antennas.

Closed-loop systems

RFID tracking systems set up within a company. Since the tracked item never leaves the company's control, it does not need to worry about using technology based on open standards.

Cold Chain

A temperature-controlled supply chain for perishable goods such as foods and pharmaceuticals, as well as for some chemical applications. In the cold chain, storage and distribution activities must maintain a given temperature range to prevent product spoilage. Specific temperature tolerances vary, depending on the actual items being shipped.

Collaborative planning, forecasting and replenishment

A general term used to describe cooperation between manufacturers and retailers to better match supply of goods with demand for them.

Command set

The set of commands a reader uses to communicate with a group of tags in the read field.

Commissioning a tag

This term is sometime used to refer to the process of writing a serial number to a tag (or programming a tag) and associating that number with the product it is put on in a database.


Two RFID systems are considered compatible if they use the same protocols, frequencies and voltage levels and are able to operate together within the same overall application (see interoperability).

Compliance Label

A label that conforms with data content and format standards, usually established by an industry.

Compliance Labeling

Many industries, including the auto, technology and aerospace industries, have established label standards for products and goods moving through the supply chain. These standards specify the use of mandatory data fields, acceptable bar code symbologies, print quality minimums and environmental considerations. Compliance labeling standards ensure that everyone practices a similar labeling approach that clearly defines the label format, usage, and the information to include on the label. There are no compliance labeling standards yet for RFID, but some consider bar-code labels with embedded UHF EPC tags as compliance labels.

Compliance testing

Testing done to confirm whether hardware or software product complies to a particular standard.


A device connected to several RFID readers to gather data from the readers. The concentrator usually performs some filtering and then passes only useful information from the readers on to a host computer.

Conducted Power

Conducted power is the RF power that is supplied by an RFID system to the antenna. Typically, it is calculated or measured at the cable to antenna connection. In the United States, Federal Communication Commission regulations require a maximum conducted power of 1 Watt.

Conductive Ink

A type of ink able to conduct a signal, usually containing powdered silver and carbon. With conductive ink, companies can draw or print circuits on a variety of materials. Conductive ink provides a cheap method for printing circuit boards on paper, for instance.


A material, such as aluminum and copper, that readily conducts electricity. Conductors have a significant impact on the performance of RFID tags. Conductors near tags can reflect RF energy in a way that reduces tag performance, and they can also detune the tag.

Conformance testing

Testing done to determine whether or not hardware or software products conform to a particular standard. See also compliance testing.

Contactless smart card

An awkward name for a credit card or loyalty card that contains an RFID chip to transmit information to a reader without having to be swiped through a reader. Such cards can speed checkout, providing consumers with more convenience.


See card operating system


See inductive coupling.


See collaborative planning, forecasting and replenishment


See central processing unit


See cyclic redundancy check

Cryptographic coprocessor

Special circuitry that perform cryptographic calculations, such as modular arithmetic and large integer calculations. These circuits are added to a standard processor core and therefore are called coprocessors.

Cyclic redundancy check

A method of checking data stored on an RFID tag to be sure that it hasn't been corrupted or some of it lost. (See Checksum.)


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