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From U to V

UART
Universal asynchronous receiver/transmitter. A device that performs asynchronous communication functions by converting parallel digital output from a DTE into serial bit transmission and vice versa.

UART buffer
Universal Asynchronous Receiver/Transmitter buffer. The UART buffer contains bytes of data being sent or received by the reader. The FIFO control register controls how the UART buffer operates.

UDC
User-defined character. See graphic.

UDF
User-defined fonts. See soft font.

UDP
1. User-defined protocol. UDP is a custom communications protocol that can be modified to meet specific host requirements. For example, you can configure User-Defined protocol to act like a Point-to-Point protocol, except that it requires an LRC and an acknowledgement from the receiver. You can also define the communications characters such as SOM, POL, or SEL, or disable these characters by setting them to null. 2. User datagram protocol. This protocol is an alternative to TCP. This protocol is the Internet standard for wireless devices. You can use UDP when you do not need a guaranteed delivery. You can also use UDP when you do not require all the services of TCP.

UDP Plus
User datagram protocol plus. This Intermec-designed protocol is based on UDP. UDP Plus provides robust wireless connectivity between Trakker Antares terminals, JANUS devices, 502X computers, and controllers/servers.

Uniform Code Council (UCC)
Previously the Uniform Product Code Council; the organization that administers the UPC and other retail standards.

Uniform Symbol Specification (USS)
The current series of symbology specifications published by AIM; they now include USS-Interleaved 2 of 5, USS-39, USS-93, USS-Codabar, USS-128, USS-49,

unit
See module.

UNIX user name
Parameter that is a variable in the DOS environment. The UNIX user name identifies the user to the Novell software running on a remote host.

unprotected field
A displayed field in which a user can enter, modify, or delete data. See also protected field.

UPC
Universal product code. A numeric, 12-digit bar code symbology used extensively in retail, particularly the grocery industry.

UPC-A
A UPC symbol that encodes a number system character, 10 digits of data and a check digit.

UPC-E
A UPC symbol that encodes six digits of data in an arrangement that occupies less area than a UPC-A symbol. Also called a "zero-suppressed" symbol, because a 10-digit UPC-A code can be compressed to a six-digit UPC-E format by suppressing redundant zeros.

UPC/EAN Code
Universal product code (UPC) is a subset of the European article numbering (EAN). The EAN code is also referred to as world product code (WPC) and international article numbering (IAN). It is used in marking items for retail sale. This code is fixed length, continuous, and weakly self-checking. It requires close printing tolerances. The character set is 0 - 9. Its maximum character density is 13.8 numeric characters per inch.

upline
1. A device that is at the computer end of a connection between a computer and a device is referred to as being upline. When devices are connected to a computer, they are connected in a line. Upline is a direction relative to the device, in contrast to downline. 2. If more than one computer is connected in a line, the upline computers usually handle data processing and the downline computers usually handle data collection and sometimes some data preprocessing.

upper memory area
The area between the 640K and 1024K. The upper memory area is physically composed of a 256K flash ROM chip (system flash) and the video memory chip. Like a PC, this area contains the BIOS and video buffers. On the reader, the upper memory area also contains PC card memory and ROM DOS. The 384K upper memory area maps just above 640K conventional memory.

utility
A program that provides general computing functions, such as file copying and program cross referencing. See also application.

validation
Comparing data with known information (patterns, ranges, check digits) to verify that the data is correct.

validation file
An ASCII file that has one entry per line. A validation file is used to ensure that the information entered in the input fields of a screen mapping screen are correct. The file is read sequentially and the last line in the ASCII file must be .

variable data field
Bar code and text fields that change from one label to the next.

variable length
A type of symbology in which the number of characters per symbol is not restricted. It is the opposite of fixed length.

variable length code
A code that can be of any length within a range of lengths, commonly with a maximum length specified and frequently with a minimum length also specified.

variable length field
A data field or data element that may vary within a prescribed minimum and maximum.

Version A
Standard 12-digit UPC symbol.

Version E
Special 6-digit shortened UPC code that requires less space and uses zero suppression.

vertical bar code
A code pattern oriented so that the axis of the symbol is perpendicular to the horizon.

viewport
A method for viewing a full size terminal or reader screen with the display. You see only a limited number of lines and characters of data at one time. Use the display as a viewport to move around and see the entire screen.

virtual display
A PC-size screen (25 x 80) accessible through the reader's smaller display for applications that need to be PC compatible. You can see 16 rows and 20 characters of the virtual display at one time. By moving the viewport, you use the reader's virtual display of 25 lines by 80 characters-the same size as a PC screen.

Virtual Wedge
A Reader Services feature that lets the reader decode bar codes, making the reader functionally equivalent to a wedge reader connected to a PC.

VMU
Vehicle mount unit. A device that is designed to be mounted on a vehicle.

void
The absence of ink in a printed bar.

volatile
Refers to memory that is not saved when power is lost or turned off. See also nonvolatile.

voting
A laser scanner parameter that takes more than one (low setting) or one more than low (high setting) matching scans from the same label to yield a good read. This is useful when scanning poor quality labels that may cause substitution errors. This is for laser scanning only.

VT/ANSI terminal emulation
A straight-through terminal emulation that causes Intermec downline devices running terminal emulation to emulate a VT100, VT220, and VT320, or ANSI terminal.