Siemens Simatic 620 - Manual (Page 209)

Glossary
Glossary-19
SIMATIC Box PC 620 Manual
A5E00131465-01
Touchscreen
The Touchscreen is a computer monitor developed and modified to recognize a
touch on the screen surface. The user can move the cursor or select an option by
touching the screen.
U
URL
Uniform Resource Locator is an address for a resource on the Internet. URLs are
used by Web browsers to locate Internet resources. A URL specifies the protocol
to be used in accessing the resource (such as http: for a World Wide Web page or
ftp: for an FTP site), the name of the server on which the resource resides (such
as //www.whitehouse.gov), and, optionally, the path to a resource (such as an
HTML document or a file on that server).
USB
Acronym for universal serial bus. A serial bus with a data transfer rate of
12 megabits per second (Mbps) for connecting peripherals to a microcomputer.
USB can connect up to 127 peripherals, such as external CD-ROM drives,
printers, modems, mice, and keyboards, to the system through a single,
general-purpose port. This is accomplished by daisy chaining peripherals together.
USB is designed to support the ability to automatically add and configure new
devices and the ability to add such devices without having to shut down and restart
the system (hot plugging).
User Interface
The software-controlled menus and screens on the monitor through which the user
communicates with the program.
User program
Contains all instructions, declarations and signal processing data that can be used
for system or a process control. It is assigned to a programmable module (for
example, CPU, FM) and can be split into smaller blocks (modules).
V
VGA
Video Graphics Array. Industrial standard graphics adapter for use with any
commonly used software.