O-S

Object class

A part of the general identifier (GID) that identifies a type or class of the item. It has to be unique within the general manager number domain. An object class can be a stock-keeping unit (SKU) or a related code, and it is assigned by the company.

Partition

Part of the serialized global trade item number (SGTIN) that indicates the point where the company prefix and the item reference are divided, because their length is not fixed.

Passive backscatter

Communication based on an electric field, which is out past the magnetic field.

Passive tags

Tags that are not able to transmit a signal by themselves, but need energy from the reader to do this.

Permeability

A material property that describes the ease with which a magnetic flux is established within the material.

Pneumatic piston label applicator

A label applicator that works as follows: As the item approaches the applicator, it passes a sensor that triggers a pneumatic piston. The applicator places the label on a vacuum plate, which is moved by the pneumatic piston to the product. The label is then pressed or blown on this item.

Probabilistic algorithm

See Asynchronous algorithm.

Programmable logic controller (PLC)

A small computer used for automation of various functions in device control, manufacturing lines, and other processes.

Q factor

Often used as a classification of the quality or efficiency of a resonant circuit, which also applies to RFID tags. "Q" in this case is for "quality."

Reader-talks-first (RTF)

Occurs when an active tag waits for an interrogation signal from the reader.

Read-only

Occurs when LF tags carry a pre-encoded tag ID, which is then matched to a database in order to retrieve information related to the tag.

Real-time location system (RTLS)

A system used to locate RFID-tagged objects within a specific area with relatively high accuracy. RTLS uses active RFID technology.

Received signal strength identification (RSSI)

A measurement of signal strength used in RTLS for locating a tagged object. The closer the tag is to the access point, the stronger the signal will be received by the interrogator. Because the location of the access points is known, the tagged object will be found according to the closest access point.

Reserved memory

Memory that carries 32-bit Access and 32-bit Kill passwords.

Right-hand rule

A way to determine the direction of the magnetic field generated by an electric current. If you grasp the electric current, carrying the wire in your right hand and having your thumb point in the direction of the current, then your fingers will circle the wire in the direction of the magnetic field.

Semi-passive tags

See Passive tags.

Serial number

A part of the general identifier. It is a unique number identifying a single item. The number has to be unique within the object class, and it is assigned by the company.

Sessions

A technique used by Generation 2 for tag management. Each tag has the capability to operate in four sessions. Each reader or group of readers interrogates tags in a separate session, and therefore does not interfere with other readers when interrogating tags. The session number is sent to a tag during the inventory round.

Slap-and-ship

The process of using just a printer that allows you to quickly create RFID labels with an electronic product code (EPC) number encoded on them.

Synchronization

The process of synchronizing the transmitting and receiving functions of readers in multiple reader environments in order to avoid interference.

Synchronous algorithm

Also known as a deterministic algorithm, this anticollision method is used by Generation 1 tags and is based on a reader going through the tags according to their unique ID.