Intermec Janus 2020 User Manual page 547

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Glossary
UPC/EAN Code
A fixed length, numeric, continuous bar code symbology that uses four
element widths. A reader that is configured to decode EAN bar codes can
decode UPC, but the reverse is not true. UPC code is a subset of EAN code. It is
a numeric, 12-digit bar code symbology used extensively in retail, particularly
the grocery industry. The character set is 0 to 9. Its maximum character density
is 13.8 numeric characters per inch.
upline
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.
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.
User-Defined protocol
A custom communications protocol that can be modified to meet specific host
requirements. For example, you can configure User-Defined to act like a
Point-to-Point protocol, except that it requires an LRC and an acknowledgment
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.
vertical reading angle
The vertical angle of a reader's laser scanner to a bar code label. The optimum
vertical reading angle is near 20 degrees.
viewport
A method for viewing a full PC-size screen (25 x 80) with the reader's 16 x 20
display. You will only see 16 lines and 20 characters of data at one time. Use
the reader's 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.
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