User manual

A-22 HS-51/HS-51X Wireless Handheld Reader User Manual
Glossary of Terms
Object Plane — An imaginary plane in the field of view, focused by a reader’s optical
system at the corresponding image plane on the sensor.
Output — A channel or communications line. Data or discrete signals that are transmitted
or displayed by a device.
Parity — An error detection routine in which one data bit in each character is set to 1 or 0
so that the total number of 1 bits in the data field is even or odd.
Port — Logical circuit for data entry and exit. (One or more ports may be included within a
single connector.)
Random Access Memory (RAM) — A data storage system used in computers, composed
of integrated circuits that allow access to stored data in any sequence without movement
of physical parts.
Read Cycle — A programmed period of time or condition during which a reader will accept
symbol input.
Read-Only Memory (ROM) — A data storage medium used in computers and other
electronics, primarily used to distribute firmware.
Substrate — The surface upon which a symbol is printed, stamped, or etched.
Symbol Transitions — The transition of bars and spaces on a symbol, used to detect the
presence of a symbol on an object.
Symbology — A symbol type, such as Data Matrix or Code 39, with special rules to
define the widths and positions of bars and spaces to represent specific numeric or
alphanumeric information.